275/65R20 tire size
A 275/65R20 tire is 34.1 inches (865 mm) tall and 10.8 inches (275 mm) wide, for a 20-inch wheel. Each sidewall is 7.0 inches (179 mm), 65% of the width, and the tire makes about 592 revolutions a mile.
Sources checked
| Dimension | 275/65R20 |
|---|---|
| Overall diameter | 34.07 in (865 mm) |
| Section width | 10.83 in (275 mm) |
| Sidewall height | 7.04 in (179 mm) |
| Aspect ratio | 65% |
| Rim diameter | 20 in |
| Circumference | 107.0 in (2,719 mm) |
| Revolutions per mile | 592 |
| Revolutions per km | 368 |
Compare 275/65R20 with another size
Metric, LT and flotation
At 60 mph on the speedometer you’re doing
61.6mph
+2.7% · the speedometer reads low
- Height
- +0.93 in (+24 mm)
- Width
- +1.67 in (+42 mm)
- Ground clearance
- +0.46 in (+12 mm)
- Each side, same wheel
- +0.84 in (+21 mm)
275/65R20 and 35x12.50R20LT side by side
| Dimension | 275/65R20 | 35x12.50R20LT | Change |
|---|---|---|---|
| Overall diameter | 34.07 in (865 mm) | 35.00 in (889 mm) | +0.93 in (+24 mm) |
| Section width | 10.83 in (275 mm) | 12.50 in (318 mm) | +1.67 in (+43 mm) |
| Sidewall height | 7.04 in (179 mm) | 7.50 in (191 mm) | +0.46 in (+12 mm) |
| Aspect ratio | 65% | 60% | |
| Rim diameter | 20 in | 20 in | |
| Circumference | 107.0 in | 110.0 in | +3.0 in |
| Revolutions per mile | 592 | 576 | −16 |
| Revolutions per km | 368 | 358 | −10 |
The working
- 275/65R20: sidewall = 275 mm × 65% = 178.8 mm = 7.04 in.
- Diameter = rim + 2 × sidewall = 20 + 2 × 7.04 = 34.07 in (865 mm).
- Circumference = π × 34.07 = 107.0 in; revolutions per mile = 63,360 ÷ 107.0 = 592.
- 35x12.50R20LT: 35.00 in tall and 12.50 in wide, as the size says.
- Sidewall = (diameter − rim) ÷ 2 = (35 − 20) ÷ 2 = 7.50 in.
- Circumference = π × 35.00 = 110.0 in; revolutions per mile = 63,360 ÷ 110.0 = 576.
- Speedometer. True speed = what it shows × new diameter ÷ old = 60 × 35.00 ÷ 34.07 = 61.6 mph.
- Ground clearance. Half the change in diameter: (35.00 − 34.07) ÷ 2 = +0.46 in.
Where the 275/65R20 numbers come from
The section width is 275 mm (10.83 inches), and each sidewall is 65% of it: 178.8 mm, or 7.04 inches. Two sidewalls and the 20-inch rim make 34.07 inches (865 mm).
One turn covers π × 34.07 = 107.0 inches, so the tire turns 592 times a mile and 368 times a kilometer.
What tire makers publish for 275/65R20
Inflated on the maker’s measuring rim. The percentage is the printed diameter against the 34.07 inches worked out above.
| Tire | Size as printed | Diameter | Width | Revs per mile |
|---|---|---|---|---|
| Toyo Open Country A/T III | LT275/65R20 | 34.1 in (+0.1%) | 11 in | 609 |
| Nitto Trail Grappler M/T | LT275/65R20 | 34.33 in (+0.7%) | 10.98 in | – |
Other 20-inch sizes against 275/65R20
Each size’s height against 275/65R20, and what a speedometer set for 275/65R20 shows at 60 mph with that size on.
| Size | Diameter | Width | Height change | At 60 mph shown |
|---|---|---|---|---|
| 245/50R20 | 29.6 in | 9.6 in | −13.0% | 52.2 mph |
| 255/50R20 | 30.0 in | 10.0 in | −11.8% | 52.9 mph |
| 255/55R20 | 31.0 in | 10.0 in | −8.9% | 54.7 mph |
| 275/55R20 | 31.9 in | 10.8 in | −6.4% | 56.2 mph |
| 275/60R20 compared | 33.0 in | 10.8 in | −3.2% | 58.1 mph |
| 285/55R20 | 32.3 in | 11.2 in | −5.1% | 56.9 mph |
| 285/60R20 | 33.5 in | 11.2 in | −1.8% | 58.9 mph |
| 33x12.50R20 | 33.0 in | 12.5 in | −3.2% | 58.1 mph |
| 35x12.50R20 compared | 35.0 in | 12.5 in | +2.7% | 61.6 mph |
275/65R20 compared
Every size: the tire size calculator. With the wheels off, the nuts go back on at your vehicle’s lug nut torque.
Questions
What is 275/65R20 in inches?
About 34.1x10.8R20: 34.1 inches tall and 10.8 inches wide on a 20-inch wheel, with 7.0-inch sidewalls. Exactly, 20 + 2 × 275 mm × 0.65 ÷ 25.4 = 34.07 inches.
How many revolutions per mile does a 275/65R20 make?
592 by its diameter: 63,360 inches in a mile ÷ 107.0 inches a turn. Tire makers’ published figures are measured under load, when the tire rolls on a slightly smaller radius, and run 2.8% to 3.3% higher in Toyo’s tables.
What flotation size is closest to 275/65R20?
Of the common 20-inch sizes, 35x12.50R20: 0.93 inches (24 mm) taller and 1.67 inches (42 mm) wider.
Is LT275/65R20 the same size as P275/65R20?
In dimensions, yes: the numbers mean the same in every metric size. The letters mark what the tire is built for, and an LT tire’s load is rated differently, so check the load index and pressure your vehicle needs before swapping one for the other.
Sources
- Bridgestone Americas: Determining tire size: P-metric, Euro-metric, LT-metric, C-type and flotation sizes, and what each number means (checked October 28, 2026)
- Toyo Tires: Extensa A/S II sizes and specifications: inflated overall diameter and width, revolutions per mile (checked October 28, 2026)
- Toyo Tires: Proxes Sport A/S sizes and specifications: inflated overall diameter and width, revolutions per mile (checked October 28, 2026)
- Toyo Tires: Open Country A/T III sizes and specifications: P-metric, LT-metric and flotation sizes, with revolutions per mile (checked October 28, 2026)
- Nitto Tire: Trail Grappler M/T sizes and specs: inflated overall diameter and width, LT-metric and flotation sizes (checked October 28, 2026)
Spotted a number that doesn’t match your manual or a source? Tell us; corrections are logged on the sources page.