SidewallMath
Tire size comparisons · Updated

265/60R18 vs 275/60R18

Close match: the 275/60R18 is 1.5% taller than the 265/60R18.

Close match. 275/60R18 is 1.5% taller than 265/60R18 (+0.47 in, 30.5 to 31.0 in). 60 mph on the speedometer is really 60.9 mph and the ride height changes by about +0.24 in.

265/60R18 vs 275/60R18 at a glance

265/60R18 and 275/60R18 compared
Measure265/60R18 (current)275/60R18 (new)Difference
Overall height30.52 in30.99 in+0.47 in (+1.55%)
Width10.43 in (265 mm)10.83 in (275 mm)+10 mm
Sidewall6.26 in6.50 in+0.24 in
Wheel18 in18 in+0 in
Circumference95.9 in97.4 in+1.5 in
Revs per mile660.8650.7−10.1

Verdict: close match

Within the 3% rule of thumb, so the speedometer, gearing and ride height change little. Going from 265/60R18 to 275/60R18 is a 1.5% increase in overall height (+0.47 in), and the vehicle sits about 0.24 in higher. The tire is 10 mm wider. The 3% rule of thumb comes from Discount Tire and 1010tires; it is not a guarantee of fit.

True speed and odometer

Speedometer after swapping 265/60R18 for 275/60R18
Speedometer showsYou are really doingDifference
35 mph35.5 mph+0.5 mph
45 mph45.7 mph+0.7 mph
55 mph55.9 mph+0.9 mph
60 mph60.9 mph+0.9 mph
65 mph66.0 mph+1.0 mph
70 mph71.1 mph+1.1 mph
75 mph76.2 mph+1.2 mph

Odometer: 1,000 indicated miles is 1,015 real miles, and 10,000 is 10,155.

The math

265/60R18: 18 + 2 × (265 × 60% ÷ 25.4) = 30.52 in. 275/60R18: 18 + 2 × (275 × 60% ÷ 25.4) = 30.99 in. Change = 30.99 ÷ 30.52 − 1 = +1.55%. True speed at 60 = 60 × 30.99 ÷ 30.52 = 60.93 mph.

Check next

Calculated from the size alone. Real tires vary a little by brand and model, and the loaded radius is a bit smaller. Confirm the wheel width range, clearance, load index and speed rating for your vehicle. See how to read a tire size, the load index chart and the speed rating chart.

Size pages: 265/60R18 · 275/60R18. More swaps: all tire size comparisons.

FAQ

Is 275/60R18 bigger than 265/60R18?

275/60R18 is 30.99 in tall against 30.52 in, so it is 1.5% taller and 10 mm wider.

What is my real speed with 275/60R18 instead of 265/60R18?

60 mph on the speedometer is really 60.9 mph and 70 is 71.1 mph.

Will 275/60R18 fit where 265/60R18 fits?

It is a close match on height (+1.5%). Fit also depends on wheel width, offset, clearance, load index and speed rating: this cannot tell you.

How much will the ride height change from 265/60R18 to 275/60R18?

About 0.24 in higher, half of the 0.47 in change in tire height.

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