My Tire Guide

315/70R18 tire size

A 315/70R18 tire stands 35.4 inches tall and 12.4 inches wide, with a 8.7-inch sidewall on an 18-inch rim.

35.4″OVERALL 35.4 IN · RIM 18 IN12.4″8.7″WIDTH · SIDEWALL
Overall height
35.4 in898 mm
Section width
12.4 in315 mm
Sidewall height
8.7 in221 mm
Rim diameter
18 in457 mm
Circumference
111.1 in2822 mm
Revolutions per mile
570354 per km
Inch size
35.4x12.4R18

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 315/70R18's overall height, the usual limit before the speedometer, ABS and transmission notice. The closest is 295/75R18, 0.2% taller (0.06 in). Wider sizes also need room in the wheel well and a rim width that suits them.

SizeHeightWidthAt 60 mph
295/75R18+0.2%+0.06 in−20 mm60.1 mph
305/70R18−1.6%−0.55 in−10 mm59.1 mph
305/75R18+1.8%+0.65 in−10 mm61.1 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 315/70R18.

SizeHeightWidthAt 60 mph
315/75R16−2.1%−0.76 in±0 mm58.7 mph
315/75R17+0.7%+0.24 in±0 mm60.4 mph
285/75R19+1.3%+0.47 in−30 mm60.8 mph
305/65R20+0.7%+0.25 in−10 mm60.4 mph

Other 18-inch sizes near 315/70R18

315 mm wide, other sidewalls

70 series, other widths

See the other sizes for this rim on 18-inch tire sizes, or other tires about this tall on 35-inch tires.

Shop 315/70R18 tires

These open each store's own list of 315/70R18 tires, where you can filter by type, load and speed rating.

315/70R18 questions

How tall is a 315/70R18 tire?

About 35.4 inches (898 mm) from the ground to the top of the tread, unloaded. On the vehicle, carrying weight, it sits a little lower.

What does 315/70R18 mean?

315 is the section width in millimetres (12.4 in). 70 means the sidewall is 70% of that width: 221 mm, or 8.7 in. R means radial construction, and 18 is the rim diameter in inches.

Can I use 295/75R18 instead of 315/70R18?

295/75R18 is 0.2% taller (0.06 in) and 20 mm narrower, which is inside the usual 3% rule. With it fitted, the speedometer shows 60 mph when you are doing 60.1 mph.

What is 315/70R18 in inches?

In inch terms it is 35.4x12.4R18: 35.4 inches tall, 12.4 inches wide, for an 18-inch rim.

How many revolutions per mile does a 315/70R18 make?

About 570 turns per mile, worked out from its unloaded circumference of 111.1 inches. Makers list slightly higher numbers for their own tires, because a loaded tire rolls on a smaller radius.