255/50R20 vs 265/50R20

265/50R20 is 0.39 inches (1.3%) taller than 255/50R20 and 0.39 inches wider. Here are both sizes side by side, drawn to scale.

Last updated · Calculated from the sidewall code · Sources

Tire sizes

Type it as it appears on the sidewall: 275/60R20, LT265/70R17 or 33x12.50R20.

Difference in height
+0.39″
265/50R20 vs 255/50R20
255/50R20265/50R20Difference
Overall diameter30.0″ 763 mm30.4″ 773 mm+0.39″ (+1.3%)
Section width10.0″ 255 mm10.4″ 265 mm+0.39″
Sidewall height5.02″ 127 mm5.22″ 133 mm+0.20″
Wheel (rim) diameter20″20″same
Circumference94.4″ 2397 mm95.6″ 2428 mm+1.2″
Revolutions per mile671663−9
Ground clearance+0.20″
255/50R2030.0″ × 10.0″30.0″265/50R2030.4″ × 10.4″30.4″
Drawn to scale: side view and tread width.

265/50R20 is 0.39″ taller (1.3%) and 0.39″ wider than 255/50R20. With a speedometer set up for 255/50R20, an indicated 60 mph is really 60.8 mph on 265/50R20, so the gauge reads 1.3% low. Ground clearance at the axle changes by +0.20″.

A 1.3% difference is within the ±3% that tire shops commonly accept without recalibrating the speedometer. Check clearance if the new tire is wider or taller.

Speedometer showsReal speed on 265/50R20
30 mph30.4 mph
45 mph45.6 mph
60 mph60.8 mph
70 mph70.9 mph
80 mph81.0 mph

What changes when you switch to 265/50R20

Sizes are theoretical, from the sidewall code. The same size can differ by a few tenths of an inch between brands and tread patterns; check the maker’s spec sheet for the exact model.

Other comparisons

Frequently asked questions

How much bigger is 265/50R20 than 255/50R20?

265/50R20 is 0.39 inches (1.3%) taller and 0.39 inches wider: 30.4" × 10.4" versus 30.0" × 10.0".

Will 265/50R20 change my speedometer?

Yes, by 1.3%. Going from 255/50R20 to 265/50R20, an indicated 60 mph is about 60.8 mph.

Can I replace 255/50R20 with 265/50R20?

Often, yes: the height difference is within the ±3% most tire shops accept. Both fit a 20" wheel; confirm the rim width, load index and clearance for your vehicle.

Do I need to regear going from 255/50R20 to 265/50R20?

Usually not for a 1.3% change. With 3.73 gears, the 265/50R20 acts like 3.68.

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