My Tire Guide

275/45R18 tire size

A 275/45R18 tire stands 27.7 inches tall and 10.8 inches wide, with a 4.9-inch sidewall on an 18-inch rim.

27.7″OVERALL 27.7 IN · RIM 18 IN10.8″4.9″WIDTH · SIDEWALL
Overall height
27.7 in705 mm
Section width
10.8 in275 mm
Sidewall height
4.9 in124 mm
Rim diameter
18 in457 mm
Circumference
87.2 in2214 mm
Revolutions per mile
727452 per km
Inch size
27.7x10.8R18

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

Sizes you can swap to

These 18-inch sizes are within two width steps and 3% of a 275/45R18's overall height, the usual limit before the speedometer, ABS and transmission notice. The closest is 255/50R18, 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
255/50R18+1.1%+0.30 in−20 mm60.6 mph
265/45R18−1.3%−0.35 in−10 mm59.2 mph
285/45R18+1.3%+0.35 in+10 mm60.8 mph
295/40R18−1.6%−0.45 in+20 mm59.0 mph
265/50R18+2.5%+0.69 in−10 mm61.5 mph
255/45R18−2.6%−0.71 in−20 mm58.5 mph
295/45R18+2.6%+0.71 in+20 mm61.5 mph
285/40R18−2.8%−0.77 in+10 mm58.3 mph

Plus and minus sizes

Changing rim size means changing the sidewall to keep the same overall height. On 16-inch or 17-inch or 19-inch or 20-inch rims, these are the closest matches to a 275/45R18.

SizeHeightWidthAt 60 mph
295/50R16−0.5%−0.13 in+20 mm59.7 mph
305/45R17+0.2%+0.06 in+30 mm60.1 mph
245/45R19−0.2%−0.06 in−30 mm59.9 mph
245/40R20−0.1%−0.03 in−30 mm59.9 mph

Other 18-inch sizes near 275/45R18

275 mm wide, other sidewalls

45 series, other widths

See the other sizes for this rim on 18-inch tire sizes.

Shop 275/45R18 tires

These open each store's own list of 275/45R18 tires, where you can filter by type, load and speed rating.

275/45R18 questions

How tall is a 275/45R18 tire?

About 27.7 inches (705 mm) from the ground to the top of the tread, unloaded. On the vehicle, carrying weight, it sits a little lower.

What does 275/45R18 mean?

275 is the section width in millimetres (10.8 in). 45 means the sidewall is 45% of that width: 124 mm, or 4.9 in. R means radial construction, and 18 is the rim diameter in inches.

Can I use 255/50R18 instead of 275/45R18?

255/50R18 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 275/45R18 in inches?

In inch terms it is 27.7x10.8R18: 27.7 inches tall, 10.8 inches wide, for an 18-inch rim.

How many revolutions per mile does a 275/45R18 make?

About 727 turns per mile, worked out from its unloaded circumference of 87.2 inches. Makers list slightly higher numbers for their own tires, because a loaded tire rolls on a smaller radius.