Tire Size Conversion Chart (By Wheel Size & Overall Diameter)
If you’re trying to change your tires and feel confused by all the numbers, you’re not alone. Tire sizing looks complicated at first, but once you understand how it works, it becomes much easier to choose the right replacement or upgrade.
This guide gives you organized tire size conversion chart by wheel size and by overall tire diameter. Whether you’re replacing factory tires, upgrading wheels, or fitting larger tires on a truck or SUV, you’ll find clear explanations and practical advice here.
Before jumping into the charts, one important rule: most experts recommend staying within a 3% difference in overall tire diameter to avoid speedometer errors and performance issues. Even the National Highway Traffic Safety Administration warns that improper tire sizing can affect braking and stability systems. We’ll explain that more below.
Tire Size Conversion Charts by Wheel Size
When we talk about wheel size, we’re talking about the diameter of the rim — the metal part the tire wraps around. It’s measured in inches.
If your tire size ends in R17, that means it fits a 17-inch wheel. That last number must match your wheel exactly. A 16-inch tire will not fit a 17-inch wheel, even if everything else looks close.
Rim diameter matters because it controls what tires you can physically install. You can change width or height slightly, but the wheel diameter cannot change unless you replace the wheels too.
This section is for people who are:
- Replacing factory tires
- Comparing slightly taller or wider options
- Upgrading the look while keeping the same wheels
If you’re not changing your wheels, start with your current size and use the chart for your wheel diameter below.
13-Inch Wheel Tire Size Conversion Chart
Thirteen-inch wheels are common on older compact cars and some small trailers. While they aren’t as popular today, many vehicles still use them.
Below are common metric tire sizes that fit 13-inch wheels, along with their overall diameter and similar inch-based sizes.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 155/80R13 | 22.8″ | 4.9″ | 22×6.00R13 |
| 165/70R13 | 22.1″ | 4.5″ | 22×6.50R13 |
| 175/70R13 | 22.6″ | 4.8″ | 23×7.00R13 |
| 185/70R13 | 23.2″ | 5.1″ | 23×7.50R13 |
14-Inch Wheel Tire Size Conversion Chart
Fourteen-inch wheels are common on older sedans, small hatchbacks, and some compact trucks. If your tire size ends in “R14,” it means it fits a 14-inch wheel.
If you’re staying with the same wheel but want a slightly taller or wider tire, this chart helps you compare options. The key is keeping the overall height close to your current tire so you don’t affect ride quality or speed accuracy too much.
Below are common 14-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 175/65R14 | 23.0″ | 4.5″ | 23×7.00R14 |
| 185/65R14 | 23.5″ | 4.7″ | 24×7.50R14 |
| 185/70R14 | 24.2″ | 5.1″ | 24×7.50R14 |
| 195/70R14 | 24.7″ | 5.4″ | 25×8.00R14 |
| 205/70R14 | 25.3″ | 5.6″ | 25×8.00R14 |
15-Inch Wheel Tire Size Conversion Chart
Fifteen-inch wheels are very common. You’ll find them on compact cars, older sedans, small SUVs, and even some light trucks.
If your tire size ends in “R15,” that means it fits a 15-inch wheel. As long as you keep the wheel the same, you can adjust the tire’s width or height slightly to change how the vehicle looks or feels.
Below are some of the most common 15-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 195/65R15 | 25.0″ | 5.0″ | 25×7.50R15 |
| 205/60R15 | 24.7″ | 4.8″ | 24×8.00R15 |
| 205/65R15 | 25.5″ | 5.2″ | 25×8.00R15 |
| 215/70R15 | 26.9″ | 5.9″ | 27×8.50R15 |
| 235/75R15 | 28.9″ | 6.9″ | 29×9.50R15 |
16-Inch Wheel Tire Size Conversion Chart
Sixteen-inch wheels are very common on sedans, small SUVs, and light trucks. If your tire size ends in “R16,” it’s made for a 16-inch wheel.
This size gives you a lot of choices. You can stay close to stock for a smooth ride, or go slightly taller for a bit more ground clearance.
Here are some common 16-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 205/55R16 | 24.9″ | 4.4″ | 25×8.00R16 |
| 215/60R16 | 26.2″ | 5.1″ | 26×8.50R16 |
| 225/60R16 | 26.6″ | 5.3″ | 27×9.00R16 |
| 235/70R16 | 29.0″ | 6.5″ | 29×9.50R16 |
| 245/75R16 | 30.5″ | 7.2″ | 31×10.00R16 |
16.5-Inch Wheel Tire Size Conversion Chart
Sixteen-and-a-half-inch wheels are mostly found on older trucks and some heavy-duty trailers. They are not very common today, but many older vehicles still use them.
It’s important to know that 16-inch and 16.5-inch wheels are not the same. A 16-inch tire will not fit a 16.5-inch wheel. Even though the numbers look close, they are completely different sizes.
Most 16.5-inch tires are listed in flotation format instead of the metric style you see on passenger cars. That means the size usually starts with the full height of the tire.
Here are some common 16.5-inch tire sizes and how they compare.
| Flotation Size | Overall Diameter (inches) | Approx. Sidewall Height (inches) | Metric Equivalent (Approx.) |
| 8.75R16.5 | 30.5″ | 7.0″ | 235/85R16 (close in height) |
| 9.50R16.5 | 31.7″ | 7.6″ | 255/85R16 (close in height) |
| 12R16.5 | 33.0″ | 8.2″ | 305/75R16 (close in height) |
17-Inch Wheel Tire Size Conversion Chart
Seventeen-inch wheels are very common on modern sedans, crossovers, SUVs, and trucks. If your tire size ends in “R17,” it’s made to fit a 17-inch wheel.
This wheel size gives you a wide range of tire choices. You can stay close to factory size for a smooth ride, or go slightly taller for a more aggressive look or extra ground clearance.
Here are some common 17-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 215/55R17 | 26.3″ | 4.7″ | 26×8.50R17 |
| 225/65R17 | 28.5″ | 5.8″ | 28×9.00R17 |
| 235/65R17 | 29.0″ | 6.0″ | 29×9.50R17 |
| 245/70R17 | 30.5″ | 6.8″ | 31×10.00R17 |
| 285/70R17 | 32.7″ | 7.9″ | 33×11.50R17 |
18-Inch Wheel Tire Size Conversion Chart
Eighteen-inch wheels are common on sport trims, midsize SUVs, and many newer sedans. If your tire size ends in “R18,” it fits an 18-inch wheel.
This size often gives a sportier look compared to smaller wheels. At the same time, it can ride a little firmer because the sidewall is usually shorter.
Here are some common 18-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 225/45R18 | 26.0″ | 4.0″ | 26×8.50R18 |
| 235/55R18 | 28.2″ | 5.1″ | 28×9.50R18 |
| 245/60R18 | 29.6″ | 5.8″ | 30×9.50R18 |
| 265/65R18 | 31.6″ | 6.8″ | 32×10.50R18 |
| 275/70R18 | 33.2″ | 7.6″ | 33×11.00R18 |
19-Inch Wheel Tire Size Conversion Chart
Nineteen-inch wheels are usually found on newer sedans, crossovers, and performance SUVs. If your tire size ends in “R19,” it fits a 19-inch wheel.
This size is often chosen for appearance and sharper handling. The trade-off is a slightly firmer ride compared to smaller wheels.
Here are some common 19-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 235/40R19 | 26.4″ | 3.7″ | 26×9.00R19 |
| 245/45R19 | 27.7″ | 4.3″ | 28×9.50R19 |
| 255/50R19 | 29.0″ | 5.0″ | 29×10.00R19 |
| 265/60R19 | 31.5″ | 6.3″ | 32×10.50R19 |
| 285/45R19 | 29.1″ | 5.0″ | 29×11.00R19 |
20-Inch Wheel Tire Size Conversion Chart
Twenty-inch wheels are common on full-size trucks, SUVs, and some sport sedans. If your tire size ends in “R20,” it fits a 20-inch wheel.
This size is popular because it balances style and performance. It looks bold, but still allows for a usable amount of sidewall for comfort.
Here are some common 20-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 245/50R20 | 29.6″ | 4.8″ | 30×9.50R20 |
| 255/55R20 | 31.0″ | 5.5″ | 31×10.00R20 |
| 275/55R20 | 31.9″ | 6.0″ | 32×11.00R20 |
| 275/60R20 | 33.0″ | 6.5″ | 33×11.00R20 |
| 305/55R20 | 33.2″ | 6.6″ | 33×12.00R20 |
21-Inch Wheel Tire Size Conversion Chart
Twenty-one-inch wheels are usually found on luxury SUVs and high-end crossovers. If your tire size ends in “R21,” it fits a 21-inch wheel.
This wheel size is mostly about appearance and handling. It gives the vehicle a sharp, modern look. The trade-off is a firmer ride because the sidewall is often shorter.
Here are some common 21-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 265/40R21 | 29.3″ | 4.2″ | 29×10.50R21 |
| 275/45R21 | 30.7″ | 4.9″ | 31×11.00R21 |
| 285/45R21 | 31.1″ | 5.0″ | 31×11.50R21 |
| 295/40R21 | 30.3″ | 4.6″ | 30×12.00R21 |
22-Inch Wheel Tire Size Conversion Chart
Twenty-two-inch wheels are common on large SUVs and full-size trucks. Some drivers choose them for a bold look, while others have them as factory equipment on higher trim levels.
If your tire size ends in “R22,” it fits a 22-inch wheel. You must keep that number the same unless you change the wheels.
Here are some common 22-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 265/40R22 | 30.3″ | 4.2″ | 30×10.50R22 |
| 275/45R22 | 31.7″ | 4.9″ | 32×11.00R22 |
| 285/45R22 | 32.1″ | 5.0″ | 32×11.50R22 |
| 305/40R22 | 31.6″ | 4.8″ | 32×12.00R22 |
| 33×12.50R22 | 33.0″ | 5.5″ | 33×12.50R22 |
23-Inch Wheel Tire Size Conversion Chart
Twenty-three-inch wheels are mostly used on custom SUVs and show builds. They are not very common from the factory, so tire choices can be limited.
If your tire size ends in “R23,” it fits a 23-inch wheel. You must match that number exactly unless you plan to replace the wheels as well.
Here are some common 23-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 275/40R23 | 31.7″ | 4.3″ | 32×11.00R23 |
| 285/40R23 | 32.0″ | 4.5″ | 32×11.50R23 |
| 305/35R23 | 31.4″ | 4.2″ | 31×12.00R23 |
| 33×12.50R23 | 33.0″ | 5.0″ | 33×12.50R23 |
24-Inch Wheel Tire Size Conversion Chart
Twenty-four-inch wheels are usually seen on custom trucks and large SUVs. Some come factory on high-end trims, but most are part of aftermarket upgrades.
If your tire size ends in “R24,” it fits a 24-inch wheel. That number must match your wheel exactly.
Here are some common 24-inch tire sizes and how they compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 275/30R24 | 30.5″ | 3.2″ | 30×10.50R24 |
| 295/35R24 | 32.1″ | 4.1″ | 32×11.50R24 |
| 305/35R24 | 32.4″ | 4.2″ | 32×12.00R24 |
| 33×12.50R24 | 33.0″ | 4.5″ | 33×12.50R24 |
26-Inch Wheel Tire Size Conversion Chart
Twenty-six-inch wheels are mostly used on custom trucks and show vehicles. They are not common on factory models, so tire choices can be limited.
If your tire size ends in “R26,” it fits a 26-inch wheel. That number must match your wheel size exactly or the tire will not mount.
Most 26-inch tires have very short sidewalls. This creates a bold look, but the ride can feel firm, especially on rough roads.
Here are a few examples to help readers understand how sizes compare.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 295/30R26 | 33.0″ | 3.5″ | 33×12.00R26 |
| 305/30R26 | 33.2″ | 3.6″ | 33×12.50R26 |
| 315/30R26 | 33.4″ | 3.7″ | 33×13.00R26 |
28-Inch Wheel Tire Size Conversion Chart
Twenty-eight-inch wheels are mostly found on custom builds. They are popular for show trucks and SUVs, but they are not common from the factory.
If your tire size ends in “R28,” it is made for a 28-inch wheel. That number has to match your wheel exactly or the tire won’t fit.
Because this size is specialized, tire options are fewer and usually more expensive. You may also need to order them instead of buying them the same day.
Here are a few common examples to help readers compare sizes.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 295/25R28 | 33.8″ | 2.9″ | 34×11.50R28 |
| 305/25R28 | 34.0″ | 3.0″ | 34×12.00R28 |
| 325/25R28 | 34.4″ | 3.2″ | 34×13.00R28 |
30-Inch Wheel Tire Size Conversion Chart
Thirty-inch wheels are almost always used for custom builds. You’ll usually see them on show trucks or heavily modified SUVs, not on factory vehicles.
If your tire size ends in “R30,” it fits a 30-inch wheel. That number must match your wheel size exactly. Even being off by half an inch means the tire won’t mount.
Tires for 30-inch wheels are limited and expensive. In many cases, they need to be special ordered, and installation costs can also be higher.
Below are a few common examples to help readers compare sizes.
| Metric Size | Overall Diameter (inches) | Sidewall Height (inches) | Closest Flotation Size |
| 305/25R30 | 36.0″ | 3.0″ | 36×12.00R30 |
| 315/25R30 | 36.2″ | 3.1″ | 36×12.50R30 |
| 325/30R30 | 37.7″ | 3.8″ | 38×13.00R30 |
Tire Conversion Charts by Overall Diameter
Overall tire diameter tells you how tall the tire stands from the road up to the top. That number affects ground clearance, how your speedometer reads, and whether the tire will hit the body or suspension when you turn.
Small changes are usually fine, but aim to stay within about 3% of your original diameter. If you go beyond that, your speedometer can be noticeably off and you might run into rubbing or braking issues.
This section is for people building lifted trucks, fitting larger off-road tires, or doing custom setups where the total tire height matters more than the rim size. If you’re just swapping the same-size tire, you don’t need this section.
21-Inch Overall Diameter Tire Size Conversion Chart
This table shows metric tire sizes that come out close to a 21-inch overall height. Use it to compare options when the total tire height (not the rim size) is what matters. The numbers are rounded and meant for quick comparison — always double-check fitment before buying.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 145/70R13 | 20.99″ | 4.00″ | 21×5.50R13 |
| 155/65R13 | 20.93″ | 3.97″ | 21×6.00R13 |
| 165/60R13 | 20.80″ | 3.90″ | 21×6.50R13 |
| 175/50R14 | 20.89″ | 3.44″ | 21×7.00R14 |
| 185/45R14 | 20.56″ | 3.28″ | 21×7.50R14 |
| 195/40R15 | 21.14″ | 3.07″ | 21×7.50R15 |
| 205/30R16 | 20.84″ | 2.42″ | 21×8.00R16 |
22-Inch Overall Diameter Tire Size Conversion Chart
This chart lists tire sizes that come out close to a 22-inch overall height. It’s helpful when you want to keep your tire height the same, even if you change wheel size.
The numbers below are rounded for easy comparison. Always double-check fitment before ordering, especially if space inside the wheel well is tight.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 155/70R13 | 21.54″ | 4.27″ | 22×6.00R13 |
| 165/65R13 | 21.45″ | 4.22″ | 22×6.50R13 |
| 175/60R14 | 22.27″ | 4.13″ | 22×7.00R14 |
| 185/55R14 | 22.01″ | 4.00″ | 22×7.50R14 |
| 195/45R15 | 21.91″ | 3.46″ | 22×7.50R15 |
| 205/40R16 | 22.46″ | 3.23″ | 22×8.00R16 |
| 215/35R17 | 22.93″ | 2.96″ | 23×8.50R17 |
23-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that are close to 23 inches tall from the ground to the top of the tire. It’s useful when you want to keep your vehicle sitting at the same height while changing wheel sizes.
The numbers are rounded to make comparison easier. They’re meant to guide you, not replace a proper fit check.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 165/70R13 | 22.09″ | 4.55″ | 23×6.50R13 |
| 175/65R14 | 22.96″ | 4.48″ | 23×7.00R14 |
| 185/60R14 | 22.74″ | 4.37″ | 23×7.50R14 |
| 195/50R15 | 22.68″ | 3.84″ | 23×7.50R15 |
| 205/45R15 | 23.26″ | 3.63″ | 23×8.00R15 |
| 215/40R16 | 22.77″ | 3.39″ | 23×8.50R16 |
| 225/35R17 | 23.20″ | 3.10″ | 23×9.00R17 |
24-Inch Overall Diameter Tire Size Conversion Chart
This chart lists tire sizes that are close to 24 inches tall from the ground to the top of the tire. It’s helpful when you want to keep the same overall height while changing wheel sizes.
The numbers below are rounded for easy comparison. They give you a solid starting point, but it’s still smart to confirm fitment before buying.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 175/70R13 | 22.64″ | 4.82″ | 23×7.00R13 |
| 185/65R14 | 23.46″ | 4.73″ | 24×7.50R14 |
| 195/60R14 | 23.21″ | 4.61″ | 24×7.50R14 |
| 205/55R15 | 23.88″ | 4.44″ | 24×8.00R15 |
| 215/50R16 | 24.46″ | 4.23″ | 24×8.50R16 |
| 225/45R17 | 24.97″ | 3.99″ | 25×9.00R17 |
| 235/40R18 | 25.40″ | 3.70″ | 25×9.50R18 |
25-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that are close to 25 inches tall from the ground to the top of the tire. It’s useful when you want to keep your vehicle at the same height but switch to a different wheel size.
The numbers are rounded so you can compare them quickly. Think of this as a guide, not a final answer. It’s always smart to double-check fit before buying.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 185/70R14 | 24.20″ | 5.10″ | 25×7.50R14 |
| 195/65R15 | 24.98″ | 4.99″ | 25×8.00R15 |
| 205/60R15 | 24.69″ | 4.84″ | 25×8.00R15 |
| 215/55R16 | 25.31″ | 4.65″ | 25×8.50R16 |
| 225/50R16 | 24.86″ | 4.43″ | 25×9.00R16 |
| 235/45R17 | 25.33″ | 4.16″ | 25×9.50R17 |
| 245/40R18 | 25.72″ | 3.86″ | 26×9.50R18 |
26-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that measure close to 26 inches tall from the ground to the top of the tire. It’s helpful if you want to keep your vehicle at roughly the same height while changing wheel sizes.
The numbers are rounded for easy comparison. They’re meant to guide you, but it’s still important to confirm fitment before making a final decision.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 195/70R14 | 24.75″ | 5.37″ | 25×8.00R14 |
| 205/65R15 | 25.49″ | 5.24″ | 26×8.00R15 |
| 215/60R16 | 26.16″ | 5.08″ | 26×8.50R16 |
| 225/55R16 | 25.74″ | 4.87″ | 26×9.00R16 |
| 235/50R17 | 26.25″ | 4.63″ | 26×9.50R17 |
| 245/45R17 | 25.68″ | 4.34″ | 26×10.00R17 |
| 255/40R18 | 26.03″ | 4.02″ | 26×10.00R18 |
27-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that are close to 27 inches tall from the ground to the top of the tire. It’s useful if you want to keep your vehicle at about the same height while changing wheel sizes.
The numbers are rounded to make them easy to compare. They’re a guide to help you narrow down options, but you should still confirm fit before buying.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 205/70R15 | 26.30″ | 5.65″ | 27×8.00R15 |
| 215/65R16 | 27.00″ | 5.50″ | 27×8.50R16 |
| 225/60R16 | 26.63″ | 5.31″ | 27×9.00R16 |
| 235/55R17 | 27.18″ | 5.09″ | 27×9.50R17 |
| 245/50R17 | 26.65″ | 4.82″ | 27×10.00R17 |
| 255/45R18 | 27.04″ | 4.52″ | 27×10.00R18 |
| 265/40R19 | 27.35″ | 4.17″ | 27×10.50R19 |
28-Inch Overall Diameter Tire Size Conversion Chart
This chart lists tire sizes that measure close to 28 inches tall from the ground to the top of the tire. It’s helpful if you want to keep your vehicle at roughly the same ride height while switching wheel sizes.
The figures below are rounded for simple comparison. They’re meant to guide you, not replace checking clearance on your own vehicle.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 215/70R15 | 26.85″ | 5.93″ | 27×8.50R15 |
| 225/65R16 | 27.52″ | 5.76″ | 28×9.00R16 |
| 235/60R16 | 27.10″ | 5.55″ | 28×9.50R16 |
| 245/55R17 | 27.61″ | 5.30″ | 28×9.50R17 |
| 255/50R18 | 28.04″ | 5.02″ | 28×10.00R18 |
| 265/45R18 | 27.39″ | 4.70″ | 28×10.50R18 |
| 275/40R19 | 27.66″ | 4.33″ | 28×11.00R19 |
29-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that are close to 29 inches tall from the ground to the top of the tire. It’s useful if you’re trying to keep your vehicle at about the same height while changing wheel sizes.
The measurements below are rounded so they’re easy to compare. They give you a solid starting point, but you should still confirm clearance before making a final choice.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 225/70R15 | 27.40″ | 6.20″ | 28×9.00R15 |
| 235/65R16 | 28.03″ | 6.01″ | 29×9.50R16 |
| 245/60R17 | 28.58″ | 5.79″ | 29×10.00R17 |
| 255/55R18 | 29.04″ | 5.52″ | 29×10.00R18 |
| 265/50R18 | 28.43″ | 5.22″ | 29×10.50R18 |
| 275/45R19 | 28.74″ | 4.87″ | 29×11.00R19 |
| 285/40R20 | 28.98″ | 4.49″ | 29×11.50R20 |
30-Inch Overall Diameter Tire Size Conversion Chart
This chart lists tire sizes that are close to 30 inches tall from the ground to the top of the tire. It’s useful if you want to keep your vehicle sitting at about the same height while switching wheel sizes.
The numbers are rounded for easy comparison. They help you narrow down options, but it’s still important to check clearance before buying.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 235/75R15 | 28.88″ | 6.94″ | 29×9.50R15 |
| 245/70R16 | 29.52″ | 6.75″ | 30×9.50R16 |
| 255/65R17 | 30.05″ | 6.52″ | 30×10.00R17 |
| 265/60R18 | 30.52″ | 6.26″ | 30×10.50R18 |
| 275/55R19 | 30.91″ | 5.96″ | 31×11.00R19 |
| 285/50R20 | 31.22″ | 5.61″ | 31×11.50R20 |
| 295/45R20 | 30.45″ | 5.23″ | 30×12.00R20 |
31-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that are close to 31 inches tall from the ground to the top of the tire. It’s helpful if you want to move to a 31-inch tire but still understand your metric size options.
The numbers below are rounded so you can compare them quickly. Use them as a guide, then confirm fitment before making a final decision.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 245/75R16 | 30.47″ | 7.23″ | 31×9.50R16 |
| 265/70R16 | 30.61″ | 7.30″ | 31×10.50R16 |
| 255/75R17 | 32.06″ | 7.53″ | 32×10.00R17 |
| 275/65R18 | 32.07″ | 7.04″ | 32×11.00R18 |
| 285/60R18 | 31.46″ | 6.73″ | 31×11.50R18 |
| 295/55R20 | 32.76″ | 6.38″ | 33×12.00R20 |
32-Inch Overall Diameter Tire Size Conversion Chart
This chart lists tire sizes that measure close to 32 inches tall from the ground to the top of the tire. It’s helpful if you’re aiming for a 32-inch setup and want to see the metric options that get you there.
The measurements are rounded for easy comparison. They’re meant to guide you, but you should always double-check clearance before installing larger tires.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 265/75R16 | 31.65″ | 7.83″ | 32×10.50R16 |
| 285/75R16 | 32.83″ | 8.42″ | 33×11.50R16 |
| 255/80R17 | 33.06″ | 8.03″ | 33×10.00R17 |
| 275/70R18 | 33.16″ | 7.58″ | 33×11.00R18 |
| 285/65R18 | 32.59″ | 7.29″ | 33×11.50R18 |
| 295/60R20 | 33.94″ | 6.97″ | 34×12.00R20 |
33-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that come out close to 33 inches tall from the ground to the top of the tire. A 33-inch tire is a common upgrade for trucks and SUVs, especially for off-road use.
The numbers below are rounded so you can compare them quickly. They’re meant to help you narrow down choices, but you should still check fitment before buying.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 285/75R16 | 32.83″ | 8.42″ | 33×11.50R16 |
| 255/85R16 | 33.07″ | 8.54″ | 33×10.00R16 |
| 275/70R18 | 33.16″ | 7.58″ | 33×11.00R18 |
| 285/70R17 | 32.71″ | 7.85″ | 33×11.50R17 |
| 295/65R18 | 33.09″ | 7.55″ | 33×12.00R18 |
| 305/55R20 | 33.21″ | 6.60″ | 33×12.50R20 |
34-Inch Overall Diameter Tire Size Conversion Chart
This chart lists tire sizes that measure close to 34 inches tall from the ground to the top of the tire. A 34-inch tire is usually chosen for lifted trucks or serious off-road builds.
The numbers below are rounded for easy comparison. They help you see which metric sizes are close to 34 inches, but you should always confirm clearance before installing larger tires.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 285/75R17 | 33.83″ | 8.42″ | 34×11.50R17 |
| 295/70R18 | 34.26″ | 8.13″ | 34×12.00R18 |
| 305/65R18 | 33.60″ | 7.80″ | 34×12.50R18 |
| 315/60R18 | 32.88″ | 7.44″ | 33×12.50R18 |
| 325/60R20 | 35.35″ | 7.68″ | 35×12.50R20 |
| 305/55R20 | 33.21″ | 6.60″ | 33×12.50R20 |
35-Inch Overall Diameter Tire Size Conversion Chartt
This chart shows tire sizes that are close to 35 inches tall from the ground to the top of the tire. A 35-inch tire is a popular upgrade for lifted trucks and serious off-road setups.
The measurements below are rounded to make comparison simple. They help you see which metric sizes are near 35 inches, but you should always confirm fitment before installing.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 315/75R16 | 34.60″ | 9.30″ | 35×12.50R16 |
| 315/70R17 | 34.36″ | 8.68″ | 35×12.50R17 |
| 325/65R18 | 34.62″ | 8.32″ | 35×13.00R18 |
| 295/70R18 | 34.26″ | 8.13″ | 34×12.00R18 |
| 305/65R20 | 35.60″ | 7.80″ | 36×12.50R20 |
| 315/60R20 | 34.88″ | 7.44″ | 35×12.50R20 |
36-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that measure close to 36 inches tall from the ground to the top of the tire. Tires this size are usually used on heavily modified trucks built for off-road use.
The numbers below are rounded to make comparison easier. They help you see which metric sizes are near 36 inches, but fitment should always be checked carefully.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 315/80R16 | 35.83″ | 9.92″ | 36×12.50R16 |
| 325/75R16 | 35.19″ | 9.60″ | 35×13.00R16 |
| 315/75R17 | 35.60″ | 9.30″ | 36×12.50R17 |
| 325/70R18 | 35.91″ | 8.96″ | 36×13.00R18 |
| 335/65R18 | 35.13″ | 8.57″ | 35×13.50R18 |
| 325/60R20 | 35.35″ | 7.68″ | 35×13.00R20 |
37-Inch Overall Diameter Tire Size Conversion Chart
This chart lists tire sizes that measure close to 37 inches tall from the ground to the top of the tire. Tires this size are usually chosen for serious off-road builds rather than daily driving.
The numbers are rounded for easy comparison. They give you a quick way to see which metric sizes are close to 37 inches, but exact measurements can vary slightly by brand.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest flotation size |
| 325/80R16 | 36.47″ | 10.24″ | 37×13.00R16 |
| 315/80R17 | 36.84″ | 9.92″ | 37×12.50R17 |
| 335/70R17 | 36.44″ | 9.23″ | 37×13.50R17 |
| 325/70R18 | 36.91″ | 8.96″ | 37×13.00R18 |
| 35×12.50R20 (metric equivalent: 325/60R20) | 35.35″ | 7.68″ | 37×12.50R20 (approx.) |
| 335/65R20 | 37.13″ | 8.57″ | 37×13.50R20 |
38-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that measure close to 38 inches tall from the ground to the top of the tire. Tires this large are mostly used on heavily modified trucks built for off-road driving.
The sizes listed here are close to 38 inches, not exact in every case. Actual height can vary slightly depending on the brand and tread design.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest Flotation Size |
| 345/80R16 | 37.73″ | 10.87″ | 38×13.50R16 |
| 335/80R17 | 38.10″ | 10.55″ | 38×13.50R17 |
| 345/75R17 | 37.37″ | 10.19″ | 38×13.50R17 |
| 355/70R18 | 37.56″ | 9.79″ | 38×14.00R18 |
| 345/65R20 | 37.64″ | 8.82″ | 38×13.50R20 |
| 375/65R20 | 39.19″ | 9.60″ | 38×15.50R20 (close) |
39-Inch Overall Diameter Tire Size Conversion Chart
This chart lists tire sizes that measure close to 39 inches tall from the ground to the top of the tire. Tires this large are usually found on serious off-road builds, not daily drivers.
Keep in mind, the listed height is an estimate. The true size can vary a little depending on the brand and tread pattern.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest Flotation Size |
| 345/85R16 | 39.07″ | 11.54″ | 39×13.50R16 |
| 375/80R17 | 40.62″ | 11.81″ | 39×14.50R17 (close) |
| 345/80R18 | 39.73″ | 10.87″ | 39×13.50R18 |
| 355/75R18 | 39.00″ | 10.49″ | 39×14.00R18 |
| 375/70R20 | 40.67″ | 10.33″ | 39×15.50R20 (close) |
40-Inch Overall Diameter Tire Size Conversion Chart
This chart shows tire sizes that are close to 40 inches tall from the ground to the top of the tire. Tires this large are usually built for extreme off-road use, not normal street driving.
The numbers listed are close estimates. Actual height can vary slightly depending on the brand and tread design.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest Flotation Size |
| 345/85R17 | 40.05″ | 11.53″ | 40×13.50R17 |
| 375/80R17 | 40.62″ | 11.81″ | 40×14.50R17 |
| 395/70R18 | 39.77″ | 10.88″ | 40×15.50R18 (close) |
| 405/70R20 | 42.32″ | 11.16″ | 40×15.50R20 (close) |
| 395/75R20 | 43.31″ | 11.65″ | 40×15.50R20 (tall) |
41–54 Inch Diameter Tire Size Conversion Chart
This section covers very large tires, starting at 41 inches and going up to 54 inches tall. Tires in this range are usually built for rock crawling, mud trucks, or show builds. They are not common for daily driving.
The chart helps you compare metric sizes with flotation sizes. It also shows the total height of the tire and the height of the sidewall, so you can see how much rubber sits between the wheel and the ground.
| Metric Size | Overall Wheel (in) | Sidewall Height (in) | Closest Flotation Size |
| 405/80R25 | 50.51″ | 12.76″ | 50×16.00R25 |
| 445/65R22.5 | 45.27″ | 11.39″ | 45×17.50R22.5 |
| 495/45R22.5 | 40.04″ | 8.77″ | 41×19.50R22.5 (close) |
| 16.9R30 | 54.00″ | 12.00″ | 54×16.90R30 |
| 21.00R25 | 63.00″ | 19.00″ | 63×21.00R25 |
How to Read a Tire Size (Quick Guide Before Using Charts)
A tire code like 275/60R20 115T gives you a lot of info.
- Section width (275): the tire width in millimeters measured from sidewall to sidewall.
- Aspect ratio (60): the sidewall height expressed as a percentage of section width (60% of 275 mm).
- Construction (R): radial construction (the most common).
- Wheel diameter (20): rim diameter in inches the tire fits.
- Load index (115) and speed rating (T): safety and performance ratings that matter when you change sizes.
If you want to calculate overall diameter yourself, use this formula:
Overall diameter (inches) = (section width mm × aspect ratio ÷ 100 × 2 ÷ 25.4) + rim diameter (inches)
Example: 225/65R17 → sidewall = 225 × 0.65 = 146.25 mm → 146.25/25.4 = 5.76 in → overall ≈ 5.76×2 + 17 = 28.52 in.
A quick rule of thumb many shops use: keeping overall diameter within ±3% of the manufacturer size will usually avoid big problems with speedometer error, gearing, and clearance.
Safe Tire Size Changes (Important Before Converting)
Changing tire sizes affects more than just how your car looks. Consider these safety and legal points before you switch:
- Keep overall diameter changes modest. A common guideline is to stay within about 3% of your original tire diameter to avoid speedometer error, ABS calibration problems, and drivetrain issues.
- Pay attention to load index and speed rating: even a visually similar tire can have a lower load capacity.
- Bigger tires can rub the wheel well, affect steering, and change handling. Test for clearance and suspension travel.
- Changing tire size can affect warranty or insurance depending on local rules—check your policy and manufacturer recommendations.
For official safety guidance, see resources from National Highway Traffic Safety Administration and sizing standards from the Tire and Rim Association.
Plus Sizing vs Minus Sizing Explained
When people talk about “plus sizing,” they mean switching to a larger wheel with a lower-profile tire that keeps overall diameter similar. The opposite—using a smaller wheel with taller sidewalls—is “minus sizing.”
Plus sizing usually improves cornering response and gives a sportier look, but increases the risk of wheel damage and harsher ride. Minus sizing can improve ride comfort and sidewall protection, but may reduce steering feel.
If you change wheel diameter, pick a tire width and aspect ratio that keep the overall diameter close to the factory to avoid mechanical or safety issues.
Conclusion
Choosing the right tire size doesn’t have to be confusing. With the conversion charts above, you can quickly compare options by wheel size or overall diameter and see what fits your vehicle safely. Just remember to keep changes within a reasonable range, match the proper load and speed ratings, and double-check clearance before installing new tires.
A small difference in size can affect handling, comfort, and speedometer accuracy, so take a few minutes to compare carefully. When in doubt, confirm your choice with a trusted tire professional. The right fit will keep your vehicle safe, comfortable, and performing the way it should.
