315/70R17 vs 35x12.50R17 tire size
A 35x12.50R17 is 0.64 inches (16 mm) taller and 0.10 inches (2 mm) wider than a 315/70R17. Fit them in place of 315/70R17 tires and the speedometer reads low: at 60 mph on it you’re doing 61.1 mph, 1.9% faster, and the vehicle sits 0.32 inches (8 mm) higher.
Sources checked
| Dimension | 315/70R17 | 35x12.50R17 | Change |
|---|---|---|---|
| Overall diameter | 34.36 in (873 mm) | 35.00 in (889 mm) | +0.64 in (+16 mm) |
| Section width | 12.40 in (315 mm) | 12.50 in (318 mm) | +0.10 in (+3 mm) |
| Sidewall height | 8.68 in (220 mm) | 9.00 in (229 mm) | +0.32 in (+9 mm) |
| Aspect ratio | 70% | 72% | |
| Rim diameter | 17 in | 17 in | |
| Circumference | 108.0 in (2,742 mm) | 110.0 in (2,793 mm) | +2.0 in |
| Revolutions per mile | 587 | 576 | −11 |
| Revolutions per km | 365 | 358 | −7 |
Check another speed or size
Metric, LT and flotation
At 60 mph on the speedometer you’re doing
61.1mph
+1.9% · the speedometer reads low
- Height
- +0.64 in (+16 mm)
- Width
- +0.10 in (+2 mm)
- Ground clearance
- +0.32 in (+8 mm)
- Each side, same wheel
- +0.05 in (+1 mm)
315/70R17 and 35x12.50R17LT side by side
| Dimension | 315/70R17 | 35x12.50R17LT | Change |
|---|---|---|---|
| Overall diameter | 34.36 in (873 mm) | 35.00 in (889 mm) | +0.64 in (+16 mm) |
| Section width | 12.40 in (315 mm) | 12.50 in (318 mm) | +0.10 in (+3 mm) |
| Sidewall height | 8.68 in (220 mm) | 9.00 in (229 mm) | +0.32 in (+9 mm) |
| Aspect ratio | 70% | 72% | |
| Rim diameter | 17 in | 17 in | |
| Circumference | 108.0 in | 110.0 in | +2.0 in |
| Revolutions per mile | 587 | 576 | −11 |
| Revolutions per km | 365 | 358 | −7 |
The working
- 315/70R17: sidewall = 315 mm × 70% = 220.5 mm = 8.68 in.
- Diameter = rim + 2 × sidewall = 17 + 2 × 8.68 = 34.36 in (873 mm).
- Circumference = π × 34.36 = 108.0 in; revolutions per mile = 63,360 ÷ 108.0 = 587.
- 35x12.50R17LT: 35.00 in tall and 12.50 in wide, as the size says.
- Sidewall = (diameter − rim) ÷ 2 = (35 − 17) ÷ 2 = 9.00 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 ÷ 34.36 = 61.1 mph.
- Ground clearance. Half the change in diameter: (35.00 − 34.36) ÷ 2 = +0.32 in.
Speedometer
A 35x12.50R17 turns 576 times a mile against the 315/70R17’s 587. With a speedometer set for 315/70R17, true speed is what it shows × 35.00 ÷ 34.36:
| Speedometer shows | True speed | Difference |
|---|---|---|
| 25 mph | 25.5 mph | +0.5 mph |
| 35 mph | 35.6 mph | +0.6 mph |
| 45 mph | 45.8 mph | +0.8 mph |
| 55 mph | 56.0 mph | +1.0 mph |
| 65 mph | 66.2 mph | +1.2 mph |
| 75 mph | 76.4 mph | +1.4 mph |
Clearance
- Ground clearance: +0.32 in (+8 mm), half the change in diameter.
- Top of the tread: +0.32 in (+8 mm), so that much less room under the fender.
- Each side, on the same wheel: +0.05 in (+1 mm), toward the suspension inside and toward the fender lip outside.
A new wheel with a different width or offset moves the tire again. The sidewall goes from 8.68 to 9.00 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 | LT315/70R17 | 34.4 in (+0.1%) | 12.7 in | 604 |
| Nitto Trail Grappler M/T | LT315/70R17 | 34.61 in (+0.7%) | 13.27 in | – |
| Toyo Open Country A/T III | 35X12.50R17LT | 34.5 in (−1.4%) | 12.5 in | 602 |
| Nitto Trail Grappler M/T | 35x12.50R17LT | 34.84 in (−0.5%) | 13.19 in | – |
Each size on its own
- 315/70R17 tire size: 34.4 × 12.4 in
- 35x12.50R17 tire size: 35.0 × 12.5 in
Other comparisons
Questions
Can I fit 35x12.50R17 tires instead of 315/70R17?
They fit the same 17-inch wheels. A 35x12.50R17 is 0.64 inches (16 mm) taller and 0.10 inches (2 mm) wider than a 315/70R17, so check three things first: that your wheels are within the 35x12.50R17’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 35x12.50R17 tires?
With a speedometer set for 315/70R17, the speedometer reads low: at 60 mph on it you’re doing 61.1 mph, 1.9% faster. The odometer is off the same way: over 1,000 miles driven it shows 981.8.
Does 35x12.50R17 change the ground clearance?
By +0.32 inches (+8 mm), half the change in diameter, at the axles and at the lowest point under them. On the same wheel, each sidewall sits 0.05 inches further out, inside and outside.
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.