315/70R17 Tire Size in Inches — Diameter, Width & Specs
A 315/70R17 tire is 34.36 inches tall (overall diameter), 12.4 inches wide, with a 8.68-inch sidewall, on a 17-inch wheel. In millimeters: 873 × 315.
Full specifications
| Measurement | Inches | Millimeters |
|---|---|---|
| Overall diameter | 34.36 in | 873 mm |
| Tire width | 12.4 in | 315 mm |
| Sidewall height | 8.68 in | 221 mm |
| Circumference | 108 in | 2742 mm |
| Revolutions per mile | 587 | |
| Wheel (rim) diameter | 17 in | 432 mm |
Same-diameter alternatives (17" rim)
No same-rim alternatives within ±1.5% in the common size list.
Popular comparisons with the 315/70R17
Load index & speed rating — how to read them
The size code is only half of the sidewall. After it comes a load index and a speed letter, like 121R. Load index 121 means one tire carries up to 3,197 lbs at its rated pressure; speed rating R means up to 106 mph. A replacement tire must meet or exceed both numbers on your vehicle's door-jamb placard. Calculate another size or compare two sizes.
How tall is a 315/70R17 tire?
34.36 inches overall diameter (873 mm), from the standard size formula. A specific brand's measured height can differ by a few tenths.
How wide is a 315/70R17?
12.4 inches (315 mm) at the casing's widest point, unloaded.
What does 315/70R17 convert to in flotation (inch) sizes?
Its diameter is 34.36", so the nearest flotation class is 34-inch tires (e.g. 34x12.50R17 where that size exists). Use the converter for exact near-matches.
Nominal geometry — method. Last verified November 12, 2026.