315/70R17 tire size
315mm wide with a 70% aspect ratio on a 17-inch wheel — 34.4 inches tall overall. Below: what it measures, what it swaps with, and which trucks run it from the factory.
Trucks that come with 315/70R17
| Truck | Years | Trims |
|---|---|---|
| Ford F-150 | 2021–2025 | Raptor (35" BFG KO2) |
| Ford F-150 | 2015–2020 | Raptor (2017-2020) |
Sizes that swap with 315/70R17
Within 3% of the original diameter — close enough to fit without a recalibration or clearance work on most trucks.
Plus and minus sizing
Same overall height on a different wheel. Going down a wheel size buys sidewall for off-road; going up is usually about looks. Gearing and speedometer stay put either way.
Compare 315/70R17 against your current size
Tire size comparison
Diameter change, speedometer error, and whether it will rub.
34.4" tall · 12.4" wide ·
34.3" tall · 11.6" wide ·
Diameter and width are close enough to stock that this is a bolt-on swap on an unmodified truck.
- Sits 0.05" lower at the axle.
- Within the range normally treated as a direct swap — no clearance work expected.
Reading this size
315/70R17 breaks down as 315mm section width, an aspect ratio of 70 (the sidewall is 70% of the width, so 8.68 inches), and a 17-inch wheel. Overall diameter is the wheel plus two sidewalls: 17 + 8.68 + 8.68 = 34.36 inches.
That last figure is the one that matters when you change size. The speedometer, odometer, transmission shift points and stability control all assume the factory diameter, so staying within a few percent keeps everything calibrated. Width matters for clearance rather than gearing — it decides whether the tire touches the suspension at full lock.
Common questions
How tall is a 315/70R17 tire?
34.36 inches in overall diameter, with a 8.68-inch sidewall on a 17-inch wheel. Section width is 12.40 inches (315mm), and it turns about 587 times per mile. Real tires vary from the nominal figure by up to half an inch depending on brand and tread.
What is equivalent to a 315/70R17?
The closest common size is 295/70R18 at 34.26 inches — -0.3% different. Anything within about 3% of the original diameter swaps on without upsetting the speedometer badly or needing a tune.
Will 315/70R17 fit my truck?
It is a factory size on the Ford F-150, so it fits those directly. On any other truck what matters is how far it is from the size fitted now — use the calculator on this page to check diameter change, speedometer error and rubbing risk against your current size.
Does going to 315/70R17 affect my speedometer?
Only if the overall diameter changes. The speedometer counts wheel rotations and multiplies by the factory tire circumference, so a larger tire makes the truck travel further per rotation than the gauge assumes and the display reads low. Around 3% is where transmission shift points and stability control calibration start to matter, and most modern trucks can be recalibrated for the new size.