265/50R14 vs 285/40R15 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

265/50R14: 24.43″ (621 mm) tall, 10.43″ (265 mm) wide, sidewall 5.22″ (133 mm) — 825 revolutions per mile.

Within the usual 3% rule

−1.87% diameter

Most fitment guides accept up to 3%. Check clearance at full lock and full suspension compression before committing.

  • Needs 15″ wheels: this tire does not fit your 14″ rims.
  • 20 mm wider: check inner clearance and that your rims are wide enough.

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Measurement265/50R14285/40R15Diff%
Overall diameter24.43″621 mm23.98″609 mm−0.46″−1.9%
Section width265.0 mm285.0 mm+20.0 mm+7.5%
Sidewall height132.5 mm114.0 mm−18.5 mm−14.0%
Rim diameter14″15″+1″+7.1%
Circumference76.76″1950 mm75.32″1913 mm−1.43″−1.9%
Revolutions per mileturns per distance; drives the odometer825513 /km841523 /km+16+1.9%
Ride height change——−0.23″ −5.8 mm

Speedometer reading

Speedo shows
60mph
97 km/h
Actual speed
58.9mph
95 km/h

Overlay

265/50R14285/40R15

Plus sizing: 265/50R14 on smaller or bigger wheels

Sizes fitted to cars that keep the overall diameter within 3% of 265/50R14 on a rim one inch smaller or up to two inches bigger, closest first.

RimSizeDiameterChangeCompare
R15 (+1) 255/45R15 24.04″ −1.6% Compare
285/40R15 23.98″ −1.9% Compare
R16 (+2) 245/45R16 24.68″ +1.0% Compare
245/40R16 23.72″ −2.9% Compare

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.

Changing wheels too? The wheel offset calculator shows how far a new wheel width and offset move the tire toward the suspension and the fender.

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 →