My Tire Guide

255/40R20 tire size

A 255/40R20 tire stands 28.0 inches tall and 10.0 inches wide, with a 4.0-inch sidewall on a 20-inch rim.

28.0″OVERALL 28.0 IN · RIM 20 IN10.0″4.0″WIDTH · SIDEWALL
Overall height
28.0 in712 mm
Section width
10.0 in255 mm
Sidewall height
4.0 in102 mm
Rim diameter
20 in508 mm
Circumference
88.1 in2237 mm
Revolutions per mile
719447 per km
Inch size
28.0x10.0R20

Compare it with any other size in the tire size calculator.

Sizes you can swap to

These 20-inch sizes are within two width steps and 3% of a 255/40R20's overall height, the usual limit before the speedometer, ABS and transmission notice. The closest is 235/45R20, 1.1% taller (0.30 in). Wider sizes also need room in the wheel well and a rim width that suits them.

SizeHeightWidthAt 60 mph
235/45R20+1.1%+0.30 in−20 mm60.6 mph
245/40R20−1.1%−0.31 in−10 mm59.3 mph
265/40R20+1.1%+0.31 in+10 mm60.7 mph
275/35R20−1.6%−0.45 in+20 mm59.0 mph
275/40R20+2.2%+0.63 in+20 mm61.3 mph
235/40R20−2.2%−0.63 in−20 mm58.7 mph
245/45R20+2.3%+0.65 in−10 mm61.4 mph
265/35R20−2.6%−0.73 in+10 mm58.4 mph

Plus and minus sizes

Changing rim size means changing the sidewall to keep the same overall height. On 18-inch or 19-inch or 21-inch or 22-inch rims, these are the closest matches to a 255/40R20.

SizeHeightWidthAt 60 mph
255/50R18+0.0%+0.01 in±0 mm60.0 mph
255/45R19+0.0%+0.00 in±0 mm60.0 mph
255/35R21−0.0%−0.00 in±0 mm60.0 mph
225/35R22+0.6%+0.17 in−30 mm60.4 mph

Other 20-inch sizes near 255/40R20

255 mm wide, other sidewalls

40 series, other widths

See the other sizes for this rim on 20-inch tire sizes.

Shop 255/40R20 tires

These open each store's own list of 255/40R20 tires, where you can filter by type, load and speed rating.

255/40R20 questions

How tall is a 255/40R20 tire?

About 28.0 inches (712 mm) from the ground to the top of the tread, unloaded. On the vehicle, carrying weight, it sits a little lower.

What does 255/40R20 mean?

255 is the section width in millimetres (10.0 in). 40 means the sidewall is 40% of that width: 102 mm, or 4.0 in. R means radial construction, and 20 is the rim diameter in inches.

Can I use 235/45R20 instead of 255/40R20?

235/45R20 is 1.1% taller (0.30 in) and 20 mm narrower, which is inside the usual 3% rule. With it fitted, the speedometer shows 60 mph when you are doing 60.6 mph.

What is 255/40R20 in inches?

In inch terms it is 28.0x10.0R20: 28.0 inches tall, 10.0 inches wide, for a 20-inch rim.

How many revolutions per mile does a 255/40R20 make?

About 719 turns per mile, worked out from its unloaded circumference of 88.1 inches. Makers list slightly higher numbers for their own tires, because a loaded tire rolls on a smaller radius.