275/60R20 vs 275/65R20 tire size
A 275/65R20 is 1.08 inches (27 mm) taller than a 275/60R20, and the same width. Fit them in place of 275/60R20 tires and the speedometer reads low: at 60 mph on it you’re doing 62.0 mph, 3.3% faster, and the vehicle sits 0.54 inches (14 mm) higher.
Sources checked
| Dimension | 275/60R20 | 275/65R20 | Change |
|---|---|---|---|
| Overall diameter | 32.99 in (838 mm) | 34.07 in (865 mm) | +1.08 in (+27 mm) |
| Section width | 10.83 in (275 mm) | 10.83 in (275 mm) | 0.00 in (0 mm) |
| Sidewall height | 6.50 in (165 mm) | 7.04 in (179 mm) | +0.54 in (+14 mm) |
| Aspect ratio | 60% | 65% | |
| Rim diameter | 20 in | 20 in | |
| Circumference | 103.6 in (2,633 mm) | 107.0 in (2,719 mm) | +3.4 in |
| Revolutions per mile | 611 | 592 | −19 |
| Revolutions per km | 380 | 368 | −12 |
Check another speed or size
Metric, LT and flotation
At 60 mph on the speedometer you’re doing
62.0mph
+3.3% · the speedometer reads low
- Height
- +1.08 in (+27 mm)
- Width
- 0.00 in (0 mm)
- Ground clearance
- +0.54 in (+14 mm)
- Each side, same wheel
- 0.00 in (0 mm)
275/60R20 and 275/65R20 side by side
| Dimension | 275/60R20 | 275/65R20 | Change |
|---|---|---|---|
| Overall diameter | 32.99 in (838 mm) | 34.07 in (865 mm) | +1.08 in (+27 mm) |
| Section width | 10.83 in (275 mm) | 10.83 in (275 mm) | 0.00 in (0 mm) |
| Sidewall height | 6.50 in (165 mm) | 7.04 in (179 mm) | +0.54 in (+14 mm) |
| Aspect ratio | 60% | 65% | |
| Rim diameter | 20 in | 20 in | |
| Circumference | 103.6 in | 107.0 in | +3.4 in |
| Revolutions per mile | 611 | 592 | −19 |
| Revolutions per km | 380 | 368 | −12 |
The working
- 275/60R20: sidewall = 275 mm × 60% = 165.0 mm = 6.50 in.
- Diameter = rim + 2 × sidewall = 20 + 2 × 6.50 = 32.99 in (838 mm).
- Circumference = π × 32.99 = 103.6 in; revolutions per mile = 63,360 ÷ 103.6 = 611.
- 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.
- Speedometer. True speed = what it shows × new diameter ÷ old = 60 × 34.07 ÷ 32.99 = 62.0 mph.
- Ground clearance. Half the change in diameter: (34.07 − 32.99) ÷ 2 = +0.54 in.
Speedometer
A 275/65R20 turns 592 times a mile against the 275/60R20’s 611. With a speedometer set for 275/60R20, true speed is what it shows × 34.07 ÷ 32.99:
| Speedometer shows | True speed | Difference |
|---|---|---|
| 25 mph | 25.8 mph | +0.8 mph |
| 35 mph | 36.1 mph | +1.1 mph |
| 45 mph | 46.5 mph | +1.5 mph |
| 55 mph | 56.8 mph | +1.8 mph |
| 65 mph | 67.1 mph | +2.1 mph |
| 75 mph | 77.5 mph | +2.5 mph |
Clearance
- Ground clearance: +0.54 in (+14 mm), half the change in diameter.
- Top of the tread: +0.54 in (+14 mm), so that much less room under the fender.
- Each side, on the same wheel: no change.
A new wheel with a different width or offset moves the tire again. The sidewall goes from 6.50 to 7.04 inches.
What tire makers publish
Inflated on the maker’s measuring rim; the percentage is against the arithmetic.
| Tire | Size as printed | Diameter | Width | Revs per mile |
|---|---|---|---|---|
| Toyo Open Country A/T III | 275/60R20 | 33 in (0.0%) | 11 in | 630 |
| Toyo Open Country A/T III | LT275/60R20 | 33 in (0.0%) | 11 in | 630 |
| 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 | – |
Each size on its own
- 275/60R20 tire size: 33.0 × 10.8 in
- 275/65R20 tire size: 34.1 × 10.8 in
Other comparisons
Questions
Can I fit 275/65R20 tires instead of 275/60R20?
They fit the same 20-inch wheels. A 275/65R20 is 1.08 inches (27 mm) taller than a 275/60R20, and the same width, so check three things first: that your wheels are within the 275/65R20’s approved rim width range, which tire makers list for each size; that it clears the fenders and suspension at full lock and full travel; and that its load index meets what your door-jamb placard asks for.
How far off is the speedometer with 275/65R20 tires?
With a speedometer set for 275/60R20, the speedometer reads low: at 60 mph on it you’re doing 62.0 mph, 3.3% faster. The odometer is off the same way: over 1,000 miles driven it shows 968.2.
Does 275/65R20 change the ground clearance?
By +0.54 inches (+14 mm), half the change in diameter, at the axles and at the lowest point under them. The width doesn’t change.
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.