275/60R18 in inches

A 275/60R18 tire is 31.0″ tall and 10.8″ wide, and fits a 18″ wheel. In inches it is written 31.0×10.8R18.

Diameter30.99″

Width10.83″

Sidewall6.50″

Drawn to scale. Nominal dimensions calculated from the size code.

Manufacturer data

How tall 275/60R18 tires really are

Heights published by General, Michelin and Toyo for all 4 tires in this size. Their published revolutions per mile work out to 30.1″ under load (below).

Real 275/60R18 tires measure 30.90–31.00″, against 30.99″ from the size code. They run both taller and shorter than the size code.

Height under load30.1″

Published revs per mile (670–671) mean the tire rolls like a 30.1″ tire on the vehicle. Use this for speedometer calibration.

Weight spread36.2–44.1 lb

The lightest (Michelin Defender LTX M/S, SL) is 7.9 lb lighter per corner than the heaviest (Toyo Observe G3-Ice, XL).

4 tires in 275/60R18

Sort by the spec you care about.

	Load					Revs/mi	Source
Michelin Defender LTX M/SAll-season	SL · 113H	30.90	36.2	10.5	2,535	671	Spec page
General Grabber A/TSportAll-terrain	SL · 113T	31.00	36.6	11.0	2,535	670	Spec page
Toyo Observe G3-IceWinter	XL · 117T	30.98	44.1	13.7	2,833	670	Spec page
General Grabber Arctic XWinter	XL · 117T	31.00	–	12.0	2,833	670	Spec page

Is 275/60R18 a 31-inch tire?

≈31″

Yes. The size code works out to 30.99″, and the 4 tires here publish 30.90–31.00″, so people call it a 31.

All 31-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

Size	Diameter ″	vs 275/60R18	Difference
265/60R18	30.52	-0.47″	-1.5%
235/75R17	30.88	-0.11″	-0.4%
275/55R19	30.91	-0.08″	-0.3%
255/60R19	31.05	+0.06″	+0.2%
255/65R18	31.05	+0.06″	+0.2%
255/70R17	31.06	+0.06″	+0.2%
275/65R17	31.07	+0.08″	+0.3%
285/60R18	31.46	+0.47″	+1.5%
245/70R18	31.50	+0.51″	+1.7%
265/65R18	31.56	+0.57″	+1.8%

How to read 275/60R18

How to read any tire size

How 275/60R18 117T is printed on the sidewall. It's the most common code among the 4 tires here (2 of them); tires in this size come in other load and speed ratings too.

1275Section width

275 mm across the widest point, or 10.83 inches. Every 275 size

260Aspect ratio

A percentage, not a measurement: the sidewall is 60% as tall as the tire is wide, which is 165.0 mm or 6.50 inches.

3RConstruction

Radial construction.

418Wheel diameter

Mounts on a 18-inch wheel. Approved wheel widths run 7.5″ to 9.5″.

5117Load index

Each tire carries up to 2,833 lb (1,285 kg) at its maximum pressure.

6TSpeed rating

Rated for up to 118 mph sustained.

XLExtra load

Printed after the size. In this size the XL tires carry up to 2,833 lb each and the standard-load tires up to 2,535 lb, as published.

Specification	Inches	Metric
Overall diameter	30.99	787 mm
Section width	10.83	275 mm
Sidewall height	6.50	165.0 mm
Circumference	97.4	2,473 mm
Revolutions per mile (calculated, unloaded)	650.7	404 per km
Revolutions per mile (published by manufacturers)	670–671	416–417 per km
Approved wheel width	7.5–9.5	191–241 mm

Speedometer error after switching to 275/60R18

Your actual speed– mph

Questions about 275/60R18

What is 275/60R18 in inches?

30.99 inches tall, 10.83 inches wide, on a 18-inch wheel. Written in inches, that is roughly 31.0×10.8R18.

How much does a 275/60R18 tire weigh?

Between 36.2 lb and 44.1 lb for the 3 tires listed here. The lightest is the Michelin Defender LTX M/S (SL); the heaviest is the Toyo Observe G3-Ice (XL).

What wheel width do I need for 275/60R18?

Manufacturers approve 7.5–9.5″ wide wheels for this size.

How many revolutions per mile does a 275/60R18 make?

Published figures run 670–671 revolutions per mile. The calculated figure is 650.7, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 275/60R18 than 265/60R18?

0.47 inches taller on paper (30.99″ vs 30.52″), which raises the axle about 0.24″. Your speedometer will read about 1.5% slow.