How Do I Know My Tire Size?
Where to find your exact tire size on the door placard and sidewall, and how to read the numbers and letters like P215/60R16.
Reviewed by Faisal Mohammad
Licensed Automotive Service Technician · 22 years' experience
Key Takeaways
- ▸Find your tire size on the driver's-side door-jamb placard or on the tire sidewall.
- ▸Read it like P215/60R16: P = passenger, 215 = width (mm), 60 = aspect ratio, R = radial, 16 = wheel diameter (in).
- ▸Match the door-placard size when replacing tires and keep all four the same.
- ▸Confirm any plus-size or upgrade fitment with a specialist for speedometer accuracy and clearance.
You can find the exact size of your vehicle's tires in two places. The easiest is the placard (a small sticker) on the inside of the driver's-side door jamb, which lists the manufacturer-recommended tire size and inflation pressure for your specific vehicle. The size is also printed directly on the tire's sidewall as a sequence of numbers and letters, for example P215/60R16.
Reading that sequence is straightforward once you know what each part means. The "P" indicates a passenger vehicle tire (you may also see "LT" for light truck). "215" is the tire's width in millimetres. "60" is the aspect ratio — the sidewall height as a percentage of the width. "R" means radial construction, and "16" is the wheel diameter in inches that the tire is designed to fit.
Always match the size on your door placard when replacing tires, and keep all four tires the same size and type unless a tire professional advises otherwise. If you're considering a different size — for a wheel upgrade or a plus-size fitment — have it confirmed by a specialist so speedometer accuracy, load rating, and clearance are all correct.
Step-by-Step Guide
- 1Look at the driver's-side door jamb placard first — it shows the factory-recommended size and pressure.
- 2The same size is printed on the tire sidewall, e.g. P215/60R16.
- 3P = passenger tire (LT = light truck); the first 3-digit number is width in millimetres.
- 4The two-digit number after the slash is the aspect ratio (sidewall height as a % of width).
- 5R = radial construction; the final number is the wheel diameter in inches.
- 6Keep all four tires the same size and type unless a professional advises otherwise.
- 7Confirm any plus-size or upgrade fitment with a specialist for speedometer accuracy and clearance.
Benefits of Proper Maintenance
- Order the correct replacement tires the first time
- Maintain accurate speedometer and odometer readings
- Preserve proper load rating and safety
- Avoid rubbing or clearance issues
- Make confident wheel-and-tire upgrade decisions
Faisal Mohammad
Licensed Automotive Service Technician · 22 years' experience
Faisal Mohammad is a licensed Automotive Service Technician with 22 years of hands-on experience in the automotive industry. He has built, repaired, and serviced thousands of vehicles across tires, wheels, brakes, suspension, and diagnostics, and reviews the tire and automotive guides published by Limitless Tire for technical accuracy.
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