Introduction
This tire height calculator helps you find the overall diameter of any tire in seconds. Just enter your tire size — like 265/70R17 or 33x12.50R15 — and the tool does the math for you. It shows the full height, sidewall height, section width, circumference, and revolutions per mile.
You can also compare two tire sizes side by side. The calculator shows exactly how much taller or shorter a new tire is and how it changes your speedometer and odometer readings. This is useful when you want to upgrade your tires or switch to a different wheel size and need to know what fits.
The tool works with both metric and flotation (inch) tire sizes. It converts between the two formats automatically, so you always see the numbers you need. A step-by-step breakdown shows how each result is calculated, and a scaled diagram lets you see the tire dimensions visually.
How to Use Our Tire Height Calculator
Enter your tire size to find the overall height, sidewall height, section width, circumference, and revolutions per mile. You can also compare two tires side by side to see the differences.
Display Order: Use the toggle at the top to choose if you want to see metric (mm) or imperial (inches) values listed first. Both units always show.
Compare a Second Tire: Turn this toggle on to add a second tire (Tire B). This unlocks the side-by-side comparison table, speedometer correction, and odometer impact tools.
Paste or Type Tire Code: Type your full tire size code into this field, like 265/70R17 or 33x12.50R15. The calculator reads the code and fills in the fields below it for you.
Notation System: Pick Metric if your tire size looks like 265/70R17. Pick Flotation if it looks like 33x12.50R15. The input fields change to match the format you choose.
Section Width: In metric mode, enter the tire width in millimeters. This is the first number in your tire code. In flotation mode, this field becomes the overall diameter in inches.
Aspect Ratio: In metric mode, enter the two-digit number after the slash. It tells you how tall the sidewall is as a percent of the width. In flotation mode, this field becomes the section width in inches.
Rim Diameter: Enter the wheel size in inches. This is the number after the "R" in your tire code.
New Wheel/Rim Size: Select Yes if you plan to switch to a different rim size. Then type the new rim diameter in inches. Select No if you are keeping your current wheels.
Press the Calculate button to see your results. Press Reset to clear everything and start over.
What Is Tire Height and How Do You Calculate It?
Tire height is the overall diameter of a tire measured from the ground to the top. It is also called the overall tire diameter. This number matters because it affects how your vehicle rides, how your speedometer reads, and whether the tire fits under your fender without rubbing.
Most tires use a metric size code like 265/70R17. The first number (265) is the tire's width in millimeters. The second number (70) is the aspect ratio, which tells you the sidewall height as a percentage of the width. The last number (17) is the wheel diameter in inches. To find the total tire height, you calculate the sidewall height, double it (because there is a sidewall on the top and bottom), and add the wheel diameter.
The Tire Height Formula
For a metric tire size, the math works like this:
- Sidewall height = Section width × (Aspect ratio ÷ 100)
- Convert the sidewall to inches by dividing by 25.4
- Overall tire height = (Sidewall height × 2) + Wheel diameter
Some tires use a flotation size code like 33x12.50R15. In this format the first number is already the overall diameter in inches, so no extra math is needed to find the height. You can use our tire conversion calculator to switch between metric and flotation notation.
Why Tire Height Matters
When you change tire sizes, even a small difference in height changes several things:
- Speedometer accuracy — A taller tire covers more ground per revolution, so your speedometer will read lower than your true speed.
- Odometer tracking — Your odometer will under-count miles with a taller tire and over-count with a shorter one. Our mileage calculator can help you track actual distances driven.
- Ground clearance — Taller tires raise the vehicle body slightly, which can help on rough roads.
- Fitment — A tire that is too tall or too wide may rub against the wheel well or suspension parts. Check your wheel offset to make sure everything clears.
- Gearing feel — Bigger tires act like a taller gear ratio. The engine works harder at low speeds but turns fewer RPMs on the highway.
Most vehicle makers recommend staying within 3% of the original tire diameter. Going beyond that can trigger warning lights, affect braking distance, and void parts of your warranty. Use our tire comparison calculator to see the exact percent change between your current and proposed tire sizes. Always check your owner's manual or ask a tire shop before making a big size change.