275/40R20 in inches

A 275/40R20 tire is 28.7″ tall and 10.8″ wide, and fits a 20″ wheel. In inches it is written 28.7×10.8R20.

Diameter28.66″

Width10.83″

Sidewall4.33″

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

Manufacturer data

How tall 275/40R20 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 24 tires in this size. Their published revolutions per mile work out to 27.8″ under load (below).

Real 275/40R20 tires measure 28.66–28.70″, against 28.66″ from the size code. They run both taller and shorter than the size code.

Height under load27.8″

Published revs per mile (725–726) mean the tire rolls like a 27.8″ tire on the vehicle. Use this for speedometer calibration.

Weight spread27.6–35.7 lb

The lightest (Toyo Extensa HP II, XL) is 8.1 lb lighter per corner than the heaviest (Michelin Latitude Sport 3, XL).

24 tires in 275/40R20

Sort by the spec you care about.

	Load					Revs/mi	Source
Toyo Extensa HP IIPerformance	XL · 106W	28.66	27.6	9.9	2,094	725	Spec page
General G-MAX RSPerformance	XL · 106Y	28.70	28.5	10.0	2,094	725	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 106(Y)	28.70	29.3	9.0	2,094	726	Spec page
Toyo Proxes Sport 2Performance	XL · 106(Y)	28.70	29.3	9.2	2,094	725	Spec page
Michelin Pilot Alpin 5Winter	XL · 106V	28.66	29.4	9.5	2,094	726	Spec page
Michelin Pilot Alpin PA4Winter	XL · 106V	28.66	30.4	10.5	2,094	726	Spec page
Michelin Pilot Sport All-Season 4Performance	XL · 106Y	28.70	30.4	10.0	2,094	726	Spec page
General G-MAX AS07Performance	XL · 106W	28.70	30.5	10.0	2,094	725	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 106(Y)	28.70	30.6	9.5	2,094	726	Spec page
Michelin Pilot Sport 4Performance	XL · 106(Y)	28.70	30.9	9.5	2,094	726	Spec page
Toyo Proxes SportPerformance	XL · 106(Y)	28.66	31.1	9.7	2,094	725	Spec page
Michelin Pilot Sport All-Season 4Performance	XL · 106V	28.70	31.3	9.0	2,094	726	Spec page
Michelin Pilot Sport 4 SUVPerformance	XL · 106Y	28.70	31.4	9.5	2,094	726	Spec page
Toyo Proxes Sport A/SPerformance	XL · 106Y	28.66	31.9	9.7	2,094	725	Spec page
BFGoodrich g-Force Phenom T/APerformance	XL · 106Y	28.66	32.3	9.0	2,094	726	Spec page
Toyo Celsius SportPerformance	XL · 106Y	28.66	33.2	9.7	2,094	725	Spec page
Michelin X-Ice SnowWinter	XL · 106H	28.66	33.3	10.5	2,094	726	Spec page
Toyo Proxes ST IIIPerformance	XL · 106W	28.66	33.4	10.1	2,094	725	Spec page
Michelin Primacy Tour A/STouring	XL · 106V	28.70	33.5	8.5	2,094	726	Spec page
Michelin Latitude Alpin LA2Winter	XL · 106V	28.66	33.9	10.0	2,094	726	Spec page
BFGoodrich g-Force COMP-2 A/S PLUSPerformance	XL · 106Y	28.66	35.1	9.0	2,094	726	Spec page
Michelin Pilot Sport 4Performance	SL · 102Y	28.70	35.3	9.0	1,874	726	Spec page
Michelin Latitude Sport 3Performance	XL · 106W	28.70	35.7	8.5	2,094	726	Spec page
Michelin Pilot Sport 4 SUVPerformance	XL · 106Y	28.70	35.7	9.0	2,094	726	Spec page

Is 275/40R20 a 29-inch tire?

≈29″

Yes. The size code works out to 28.66″, and the 24 tires here publish 28.66–28.70″, so people call it a 29.

All 29-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

Size	Diameter ″	vs 275/40R20	Difference
295/35R20	28.13	-0.53″	-1.9%
345/30R20	28.15	-0.51″	-1.8%
235/45R20	28.33	-0.33″	-1.2%
265/40R20	28.35	-0.31″	-1.1%
305/35R20	28.41	-0.26″	-0.9%
245/45R20	28.68	+0.02″	+0.1%
315/35R20	28.68	+0.02″	+0.1%
285/40R20	28.98	+0.31″	+1.1%
255/45R20	29.04	+0.37″	+1.3%
235/50R20	29.25	+0.59″	+2.1%

How to read 275/40R20

How to read any tire size

How 275/40R20 106Y is printed on the sidewall. It's the most common code among the 24 tires here (8 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

240Aspect ratio

A percentage, not a measurement: the sidewall is 40% as tall as the tire is wide, which is 110.0 mm or 4.33 inches.

3RConstruction

Radial construction.

420Wheel diameter

Mounts on a 20-inch wheel. Approved wheel widths run 9.0″ to 11.0″.

5106Load index

Each tire carries up to 2,094 lb (950 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 2,094 lb each and the standard-load tires up to 1,874 lb, as published.

Specification	Inches	Metric
Overall diameter	28.66	728 mm
Section width	10.83	275 mm
Sidewall height	4.33	110.0 mm
Circumference	90.0	2,287 mm
Revolutions per mile (calculated, unloaded)	703.7	437 per km
Revolutions per mile (published by manufacturers)	725–726	450–451 per km
Approved wheel width	9.0–11.0	229–279 mm

Speedometer error after switching to 275/40R20

Your actual speed– mph

Questions about 275/40R20

What is 275/40R20 in inches?

28.66 inches tall, 10.83 inches wide, on a 20-inch wheel. Written in inches, that is roughly 28.7×10.8R20.

How much does a 275/40R20 tire weigh?

Between 27.6 lb and 35.7 lb for the 24 tires listed here. The lightest is the Toyo Extensa HP II (XL); the heaviest is the Michelin Latitude Sport 3 (XL).

What wheel width do I need for 275/40R20?

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

How many revolutions per mile does a 275/40R20 make?

Published figures run 725–726 revolutions per mile. The calculated figure is 703.7, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 275/40R20 than 305/35R20?

0.26 inches taller on paper (28.66″ vs 28.41″), which raises the axle about 0.13″. Your speedometer will read about 0.9% slow.