ElpiAuto315/70R17 in inches
A 315/70R17 is 34.4″ tall and 12.4″ wide on a 17″ wheel — about a 34.4x12.4R17 in inch/flotation notation, a 34-inch tire.
Your tire size
e.g. 235/75R15, 33X12.50R15, or 225/45R17 91V
Sizes close to 315/70R17
No standard metric size lands exactly on 315/70R17. The best compromise is 295/75R17 (+0.2% height, −20 mm width); the list is ranked by height and width together, all on a 17″ wheel within ±3%.
| Size | Diameter | Height vs 315/70R17 | Width vs 315/70R17 |
|---|---|---|---|
| 295/75R17 | 34.4″ · 874 mm | +0.2% | −20 mm |
| 305/70R17 | 33.8″ · 859 mm | −1.6% | −10 mm |
| 325/70R17 | 34.9″ · 887 mm | +1.6% | +10 mm |
| 335/65R17 | 34.1″ · 867 mm | −0.6% | +20 mm |
| 305/75R17 | 35.0″ · 889 mm | +1.9% | −10 mm |
315/70R17 dimensions
Computed from the size code; moulded tires vary by brand by roughly 1–3%.
| Dimension | Inches | Millimetres |
|---|---|---|
| Overall diameter | 34.4″ | 873 |
| Section width | 12.40″ | 315 |
| Sidewall height | 8.68″ | 220 |
| Circumference | 108.0″ | 2742 |
| Revolutions per mile | 587 | — |
| Revolutions per km | — | 365 |
The same height on other wheels
If you are changing wheel diameter but want to keep a 34.4″ overall height, these metric sizes come closest (within 2%).
| Wheel | Size | Diameter | Difference |
|---|---|---|---|
| 15″ | 305/80R15 | 34.2″ | −0.4% |
| 16″ | 335/70R16 | 34.5″ | +0.3% |
| 18″ | 345/60R18 | 34.3″ | −0.2% |
| 20″ | 305/60R20 | 34.4″ | +0.1% |
| 22″ | 285/55R22 | 34.3″ | −0.1% |
Wheel width and neighbouring sizes
A 315 mm-wide tire mounts on 9.5–12.0″ wide wheels (the usual approved range; the middle is ideal).
One step down is 285/75R17: −1.5% in diameter. With a speedometer calibrated for 315/70R17, an indicated 60 mph would be 59.1 mph on 285/75R17.
One step up is 35X12.50R17: +1.9% in diameter. With a speedometer calibrated for 315/70R17, an indicated 60 mph would be 61.1 mph on 35X12.50R17.
Figures are geometric: overall diameter = wheel + 2 × sidewall, 25.4 mm per inch. Check the tire maker's data sheet for the exact moulded size before buying.