245/40R15 vs 26x10.00R15 tire size comparison

Change either size and everything below updates.

Start from your car make, model, year
Current tire size
/R
xR
New tire size
/R
xR

Width in mm · aspect = sidewall height as a % of width · rim in inches

Flotation (LT) sizes, all in inches: overall diameter × section width, then rim

Not a realistic swap

+14.45% diameter

A diameter change this large does not fit a stock car without a lift or other modifications. Start from the sizes your car came with.

Check what fits your car Factory tire sizes for every make, model and year.

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Measurement245/40R1526x10.00R15Diff%
Overall diameter22.72″577 mm26.00″660 mm+3.28″+14.5%
Section width245.0 mm254.0 mm+9.0 mm+3.7%
Sidewall height98.0 mm139.7 mm+41.7 mm+42.6%
Rim diameter15″15″0″0.0%
Circumference71.37″1813 mm81.68″2075 mm+10.32″+14.5%
Revolutions per mileturns per distance; drives the odometer888552 /km776482 /km−112−12.6%
Ride height change——+1.64″ +41.7 mm

Speedometer reading

Speedo shows
60mph
97 km/h
Actual speed
68.7mph
111 km/h

Overlay

245/40R1526x10.00R15

How to use the tire size calculator

Put your current tire size — width, aspect ratio and rim diameter — into the first form, then your desired size into the second. You’ll get the difference between the new and the old size, plus the speedometer reading difference and your actual speed on the new set. Both metric and flotation (LT inch) sizes are supported.

The calculator helps you decide whether a set of tires and wheels will fit your car. To compare tires by brand and model instead, use our tire comparison tool; to look up factory sizes, browse by car make.

Reading a tire size

225/45R17
225
Section width in millimetres
45
Aspect ratio — sidewall height as a % of width
R
Radial construction
17
Rim diameter in inches

Full guide to the tire sidewall →