Tire size reference

275/60R20 tire size: 32.99 in tall

Diameter, sidewall, width and revs per mile for 275/60R20, the common sizes within 3% of its diameter, and what each one does to the speedometer.

Open 275/60R20 in the tire size calculator
In short

275/60R20, in short: 32.99 in (838 mm) tall and 275 mm (10.83 in) wide, with a 6.50 in (165.0 mm) sidewall, for a 20-inch wheel. Circumference is 103.65 in, so it turns about 611 times per mile (calculated from the nominal size).

Overall diameter32.99 in · 838 mm
Section width275 mm · 10.83 in
Sidewall height6.50 in · 165.0 mm
Circumference103.65 in
Revs per mile (calculated)611
In inches33.0x10.8R20

Calculated from the size: sidewall = 275 × 60% = 165.00 mm; diameter = 2 × 6.496 in + 20 in; revs per mile = 63,360 ÷ (π × diameter).

Sizes within 3% of 275/60R20

8 common sizes come within ±3% of 32.99 in: 2 on the same 20-inch wheel, 2 plus-size and 4 minus-size. The last column is what the speedometer shows when the vehicle, set up for 275/60R20, is doing a true 60 mph.

SizeFitDiameterDifferenceWidthSidewallRevs/mile (calc.)Speedometer at a true 60
275/60R20This size32.99 in-275 mm6.50 in61160.0 mph
275/65R18Minus 232.07 in-2.78%275 mm7.04 in62961.7 mph
285/65R18Minus 232.59 in-1.23%285 mm7.29 in61960.7 mph
265/70R18Minus 232.61 in-1.17%265 mm7.30 in61960.7 mph
275/70R18Minus 233.16 in+0.50%275 mm7.58 in60859.7 mph
265/60R20Same wheel32.52 in-1.43%265 mm6.26 in62060.9 mph
285/60R20Same wheel33.46 in+1.43%285 mm6.73 in60359.2 mph
285/45R22Plus 232.10 in-2.71%285 mm5.05 in62861.7 mph
275/50R22Plus 232.83 in-0.50%275 mm5.41 in61460.3 mph

A taller tire makes the speedometer read low, a shorter one high. Plus-sizing keeps the diameter close by trading sidewall for wheel. Any replacement needs a load index at least as high as the vehicle's tire placard calls for, and a wheel width the tire is approved for.

275/60R20 compared

275/60R20 side by side with 275/65R20 and 275/55R20: dimension by dimension, and what the swap does to the speedometer.

275/60R20 vs 275/65R20

+3.28% diameter
275/60R20275/65R20Difference
Overall diameter32.99 in34.07 in+1.08 in (+3.3%)
Section width275 mm275 mm+0 mm
Sidewall height6.50 in7.04 in+0.54 in
Wheel diameter20 in20 in+0 in
Circumference103.6 in107.0 in+3.4 in
Revs per mile (calc.)611592-19

275/65R20 is 3.3% taller than 275/60R20. At a true 60 mph the speedometer shows 58.1 mph (it reads low), and when it shows 60 you're doing 62.0 mph.

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275/60R20 vs 275/55R20

-3.28% diameter
275/60R20275/55R20Difference
Overall diameter32.99 in31.91 in-1.08 in (-3.3%)
Section width275 mm275 mm+0 mm
Sidewall height6.50 in5.95 in-0.54 in
Wheel diameter20 in20 in+0 in
Circumference103.6 in100.2 in-3.4 in
Revs per mile (calc.)611632+21

275/55R20 is 3.3% shorter than 275/60R20. At a true 60 mph the speedometer shows 62.0 mph (it reads high), and when it shows 60 you're doing 58.0 mph.

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Which vehicles come with 275/60R20

Vehicles sold in the US that have 275/60R20 as the standard size on these trims, with the page that lists it. The tire placard on the driver's door edge or post has the size, and the load and inflation, for the exact vehicle.

Vehicles mostly picked from Carscoops: 2025 U.S. car sales, full-year top 25 (Car and Driver data, January 2026).

FAQ

Questions about 275/60R20 tires

How tall is a 275/60R20 tire?
32.99 inches (838 mm) overall. The sidewall is 275 × 60% = 165.00 mm (6.50 in); twice that plus the 20-inch wheel gives 32.99 in. That's the nominal size: the maker's spec sheet lists the measured diameter for each tire.
What is 275/60R20 in inches?
About 33.0x10.8R20: 32.99 in tall, 10.83 in wide, for a 20-inch wheel, with a 6.50 in sidewall.
How many revolutions per mile does a 275/60R20 tire make?
About 611, calculated as 63,360 in ÷ (103.65 in circumference). Makers measure revs per mile under load, where the tire squats a little, so their published figure for a given tire is usually somewhat higher.
What size can replace 275/60R20?
The usual guideline is to stay within 3% of the original 32.99 in diameter, which keeps the speedometer, gearing and stability systems close. The closest common ones are 275/70R18 (+0.5%, 18-inch wheel); 275/50R22 (-0.5%, 22-inch wheel); 265/70R18 (-1.2%, 18-inch wheel). A replacement also needs a load index at least as high as the vehicle's placard calls for and a wheel of the right width.
275/60R20 vs 275/65R20: what's the difference?
275/65R20 is 3.3% taller than 275/60R20. At a true 60 mph the speedometer shows 58.1 mph (it reads low), and when it shows 60 you're doing 62.0 mph. That's outside the usual 3% guideline, so check clearance and the speedometer before you fit it.
Which vehicles come with 275/60R20 tires?
It's the standard size on the 2025 Ford F-150 STX, King Ranch, Platinum; 2025 Chevrolet Silverado 1500 Custom, LTZ, High Country; 2025 GMC Sierra 1500 Elevation, Denali, AT4. Always go by the size on the vehicle's tire placard (driver's door edge or post) or in the owner's manual.
Sources

How these numbers are worked out

Checked October 2026. Dimensions are nominal, calculated from the size designation. A real tire's diameter, width and revs per mile vary by brand, tread depth, rim width and load, so check the maker's spec sheet.

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