275/35R18 in inches

A 275/35R18 tire is 25.6″ tall and 10.8″ wide, and fits a 18″ wheel. In inches it is written 25.6×10.8R18.

Diameter25.58″

Width10.83″

Sidewall3.79″

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

Manufacturer data

How tall 275/35R18 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 18 tires in this size. Their published revolutions per mile work out to 24.7–24.8″ under load (below).

Real 275/35R18 tires measure 25.50–25.60″, against 25.58″ from the size code. They run both taller and shorter than the size code.

Height under load24.7–24.8″

Published revs per mile (812–816) mean the tire rolls like a 24.7–24.8″ tire on the vehicle. Use this for speedometer calibration.

Weight spread23.8–31.3 lb

The lightest (Michelin Pilot Sport Cup 2 Connect, XL) is 7.5 lb lighter per corner than the heaviest (Michelin Pilot Sport PS2, SL).

18 tires in 275/35R18

Sort by the spec you care about.

	Load					Revs/mi	Source
Michelin Pilot Sport Cup 2 ConnectPerformance	XL · 99(Y)	25.60	23.8	7.2	1,709	814	Spec page
General G-MAX RSPerformance	SL · 95Y	25.60	24.3	10.0	1,521	812	Spec page
Toyo Proxes RPerformance	SL · 95W	25.55	25.4	3.6	1,521	813	Spec page
Toyo Proxes RRPerformance	LL · 87	25.55	26.0	3.6	1,201	813	Spec page
Toyo Proxes Sport 2Performance	XL · 99Y	25.60	26.2	9.2	1,709	813	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 99(Y)	25.60	26.3	9.5	1,709	814	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 99(Y)	25.60	26.7	9.0	1,709	814	Spec page
Toyo Proxes Sport RPerformance	XL · 99W	25.60	26.9	7.2	1,709	813	Spec page
BFGoodrich g-Force Rival SPerformance	SL · 87W	25.55	27.1	7.2	1,201	814	Spec page
BFGoodrich g-Force Rival+Performance	SL · 87W	25.55	27.1	7.2	1,201	814	Spec page
Toyo Proxes Sport A/SPerformance	XL · 99Y	25.55	27.4	9.7	1,709	813	Spec page
BFGoodrich g-Force Phenom T/APerformance	XL · 99Y	25.55	27.5	8.0	1,709	814	Spec page
Michelin Pilot Sport All-Season 4Performance	XL · 99Y	25.50	27.7	10.0	1,709	816	Spec page
Toyo Proxes R888RPerformance	SL · 95Y	25.55	28.0	6.3	1,521	813	Spec page
BFGoodrich g-Force COMP-2 A/S PLUSPerformance	XL · 99W	25.55	28.5	9.0	1,521	814	Spec page
Michelin Pilot Sport All-Season 4Performance	SL · 95(Y)	25.60	29.3	10.0	1,521	814	Spec page
Toyo Proxes RA1Performance	SL	25.60	30.0	8.0	1,521	812	Spec page
Michelin Pilot Sport PS2Performance	SL · 87(Y)	25.60	31.3	9.5	1,201	814	Spec page

Is 275/35R18 a 26-inch tire?

≈26″

Close. The size code works out to 25.58″, and the 18 tires here publish 25.50–25.60″, so people call it a 26.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

Size	Diameter ″	vs 275/35R18	Difference
225/40R18	25.09	-0.49″	-1.9%
265/35R18	25.30	-0.28″	-1.1%
235/40R18	25.40	-0.18″	-0.7%
315/30R18	25.44	-0.14″	-0.5%
215/45R18	25.62	+0.04″	+0.2%
245/40R18	25.72	+0.14″	+0.5%
285/35R18	25.85	+0.28″	+1.1%
335/30R18	25.91	+0.33″	+1.3%
225/45R18	25.97	+0.39″	+1.5%
255/40R18	26.03	+0.45″	+1.8%

How to read 275/35R18

How to read any tire size

How 275/35R18 99Y is printed on the sidewall. It's the most common code among the 18 tires here (4 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

235Aspect ratio

A percentage, not a measurement: the sidewall is 35% as tall as the tire is wide, which is 96.3 mm or 3.79 inches.

3RConstruction

Radial construction.

418Wheel diameter

Mounts on a 18-inch wheel. Approved wheel widths run 9.0″ to 11.0″.

599Load index

Each tire carries up to 1,709 lb (775 kg) at its maximum pressure.

6YSpeed rating

Rated for up to 186 mph sustained.

XLExtra load

Printed after the size. In this size the XL tires carry up to 1,709 lb each and the standard-load tires up to 1,521 lb, as published.

Specification	Inches	Metric
Overall diameter	25.58	650 mm
Section width	10.83	275 mm
Sidewall height	3.79	96.3 mm
Circumference	80.4	2,041 mm
Revolutions per mile (calculated, unloaded)	788.5	490 per km
Revolutions per mile (published by manufacturers)	812–816	505–507 per km
Approved wheel width	9.0–11.0	229–279 mm

Speedometer error after switching to 275/35R18

Your actual speed– mph

Questions about 275/35R18

What is 275/35R18 in inches?

25.58 inches tall, 10.83 inches wide, on a 18-inch wheel. Written in inches, that is roughly 25.6×10.8R18.

How much does a 275/35R18 tire weigh?

Between 23.8 lb and 31.3 lb for the 18 tires listed here. The lightest is the Michelin Pilot Sport Cup 2 Connect (XL); the heaviest is the Michelin Pilot Sport PS2 (SL).

What wheel width do I need for 275/35R18?

Manufacturers approve 9.0–11.0″ wide wheels for this size.

How many revolutions per mile does a 275/35R18 make?

Published figures run 812–816 revolutions per mile. The calculated figure is 788.5, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 275/35R18 than 315/30R18?

0.14 inches taller on paper (25.58″ vs 25.44″), which raises the axle about 0.07″. Your speedometer will read about 0.5% slow.