245/70R17 tire size
A 245/70R17 tire is 30.5 inches (775 mm) tall and 9.6 inches (245 mm) wide, for a 17-inch wheel. Each sidewall is 6.8 inches (172 mm), 70% of the width, and the tire makes about 661 revolutions a mile.
Sources checked
| Dimension | 245/70R17 |
|---|---|
| Overall diameter | 30.50 in (775 mm) |
| Section width | 9.65 in (245 mm) |
| Sidewall height | 6.75 in (172 mm) |
| Aspect ratio | 70% |
| Rim diameter | 17 in |
| Circumference | 95.8 in (2,434 mm) |
| Revolutions per mile | 661 |
| Revolutions per km | 411 |
Compare 245/70R17 with another size
Metric, LT and flotation
At 60 mph on the speedometer you’re doing
61.9mph
+3.2% · the speedometer reads low
- Height
- +0.96 in (+25 mm)
- Width
- 0.00 in (0 mm)
- Ground clearance
- +0.48 in (+12 mm)
- Each side, same wheel
- 0.00 in (0 mm)
245/70R17 and 245/75R17 side by side
| Dimension | 245/70R17 | 245/75R17 | Change |
|---|---|---|---|
| Overall diameter | 30.50 in (775 mm) | 31.47 in (799 mm) | +0.97 in (+24 mm) |
| Section width | 9.65 in (245 mm) | 9.65 in (245 mm) | 0.00 in (0 mm) |
| Sidewall height | 6.75 in (172 mm) | 7.23 in (184 mm) | +0.48 in (+12 mm) |
| Aspect ratio | 70% | 75% | |
| Rim diameter | 17 in | 17 in | |
| Circumference | 95.8 in | 98.9 in | +3.1 in |
| Revolutions per mile | 661 | 641 | −20 |
| Revolutions per km | 411 | 398 | −13 |
The working
- 245/70R17: sidewall = 245 mm × 70% = 171.5 mm = 6.75 in.
- Diameter = rim + 2 × sidewall = 17 + 2 × 6.75 = 30.50 in (775 mm).
- Circumference = π × 30.50 = 95.8 in; revolutions per mile = 63,360 ÷ 95.8 = 661.
- 245/75R17: sidewall = 245 mm × 75% = 183.8 mm = 7.23 in.
- Diameter = rim + 2 × sidewall = 17 + 2 × 7.23 = 31.47 in (799 mm).
- Circumference = π × 31.47 = 98.9 in; revolutions per mile = 63,360 ÷ 98.9 = 641.
- Speedometer. True speed = what it shows × new diameter ÷ old = 60 × 31.47 ÷ 30.50 = 61.9 mph.
- Ground clearance. Half the change in diameter: (31.47 − 30.50) ÷ 2 = +0.48 in.
Where the 245/70R17 numbers come from
The section width is 245 mm (9.65 inches), and each sidewall is 70% of it: 171.5 mm, or 6.75 inches. Two sidewalls and the 17-inch rim make 30.50 inches (775 mm).
One turn covers π × 30.50 = 95.8 inches, so the tire turns 661 times a mile and 411 times a kilometer.
What tire makers publish for 245/70R17
Inflated on the maker’s measuring rim. The percentage is the printed diameter against the 30.50 inches worked out above.
| Tire | Size as printed | Diameter | Width | Revs per mile |
|---|---|---|---|---|
| Toyo Open Country A/T III | 245/70R17 | 30.6 in (+0.3%) | 9.8 in | 680 |
| Toyo Open Country A/T III | LT245/70R17 | 30.6 in (+0.3%) | 9.8 in | 680 |
Other 17-inch sizes against 245/70R17
Each size’s height against 245/70R17, and what a speedometer set for 245/70R17 shows at 60 mph with that size on.
| Size | Diameter | Width | Height change | At 60 mph shown |
|---|---|---|---|---|
| 215/45R17 | 24.6 in | 8.5 in | −19.3% | 48.4 mph |
| 215/50R17 | 25.5 in | 8.5 in | −16.5% | 50.1 mph |
| 215/55R17 | 26.3 in | 8.5 in | −13.7% | 51.8 mph |
| 215/60R17 | 27.2 in | 8.5 in | −11.0% | 53.4 mph |
| 225/45R17 | 25.0 in | 8.9 in | −18.1% | 49.1 mph |
| 225/50R17 | 25.9 in | 8.9 in | −15.2% | 50.9 mph |
| 225/55R17 | 26.7 in | 8.9 in | −12.3% | 52.6 mph |
| 225/60R17 | 27.6 in | 8.9 in | −9.4% | 54.3 mph |
| 225/65R17 | 28.5 in | 8.9 in | −6.5% | 56.1 mph |
| 235/55R17 | 27.2 in | 9.3 in | −10.9% | 53.5 mph |
| 235/60R17 | 28.1 in | 9.3 in | −7.9% | 55.3 mph |
| 235/65R17 | 29.0 in | 9.3 in | −4.8% | 57.1 mph |
| 245/65R17 compared | 29.5 in | 9.6 in | −3.2% | 58.1 mph |
| 245/75R17 compared | 31.5 in | 9.6 in | +3.2% | 61.9 mph |
| 255/70R17 compared | 31.1 in | 10.0 in | +1.8% | 61.1 mph |
| 265/65R17 | 30.6 in | 10.4 in | +0.2% | 60.1 mph |
| 265/70R17 | 31.6 in | 10.4 in | +3.6% | 62.2 mph |
| 275/70R17 | 32.2 in | 10.8 in | +5.4% | 63.3 mph |
| 285/70R17 | 32.7 in | 11.2 in | +7.2% | 64.3 mph |
| 285/75R17 | 33.8 in | 11.2 in | +10.9% | 66.5 mph |
| 315/70R17 | 34.4 in | 12.4 in | +12.6% | 67.6 mph |
| 33x12.50R17 | 33.0 in | 12.5 in | +8.2% | 64.9 mph |
| 35x12.50R17 | 35.0 in | 12.5 in | +14.7% | 68.8 mph |
| 37x12.50R17 | 37.0 in | 12.5 in | +21.3% | 72.8 mph |
245/70R17 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 245/70R17 in inches?
About 30.5x9.6R17: 30.5 inches tall and 9.6 inches wide on a 17-inch wheel, with 6.8-inch sidewalls. Exactly, 17 + 2 × 245 mm × 0.70 ÷ 25.4 = 30.50 inches.
How many revolutions per mile does a 245/70R17 make?
661 by its diameter: 63,360 inches in a mile ÷ 95.8 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.
Is LT245/70R17 the same size as P245/70R17?
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.