Tire size
31x10.50R15 in metric
A 31x10.50R15 tire is 31.0 inches (787 mm) tall and 10.5 inches (267 mm) wide, on a 15-inch wheel. Its sidewall is 76% of its width.
| 31x10.50R15 | Inches | Metric |
|---|---|---|
| Overall diameter (height) | 31.0 in | 787 mm |
| Section width | 10.5 in | 267 mm |
| Sidewall height | 8.0 in | 203 mm |
| Wheel (rim) diameter | 15 in | 381 mm |
| Circumference | 97.4 in | 2474 mm |
| Revolutions | 651 per mile | 404 per km |
How it's worked out
Inch sizes give the height first: 31x10.50R15 is 31.0 in tall and 10.5 in wide for a 15 in wheel, so each sidewall is (31.0 - 15) / 2 = 8.0 in.
Similar sizes
Sizes within about 3.5% of the height of 31x10.50R15. The last column is your real speed at an indicated 60 mph if your speedometer was set for 31x10.50R15.
| Size | Height | vs 31x10.50R15 | Real speed at 60 mph shown |
|---|---|---|---|
| 275/60R18 | 31.0 in | -0.0% | 60.0 mph |
| 255/55R20 | 31.0 in | +0.1% | 60.1 mph |
| 255/65R18 | 31.1 in | +0.2% | 60.1 mph |
| 255/70R17 | 31.1 in | +0.2% | 60.1 mph |
| 275/65R17 | 31.1 in | +0.2% | 60.1 mph |
| 275/50R20 | 30.8 in | -0.6% | 59.7 mph |
| 285/50R20 | 31.2 in | +0.7% | 60.4 mph |
| 265/70R16 | 30.6 in | -1.3% | 59.2 mph |
Going bigger from 31x10.50R15
If 31x10.50R15 is your stock size, these are the commonly sold axle ratios that come closest to your stock overall gearing on bigger tires.
| Your ratio now | On 33s | On 35s | On 37s |
|---|---|---|---|
| 3.21 | 3.42 exact 3.42 | 3.55 exact 3.62 | 3.91 exact 3.83 |
| 3.42 | 3.73 exact 3.64 | 3.91 exact 3.86 | 4.10 exact 4.08 |
| 3.55 | 3.73 exact 3.78 | 4.10 exact 4.01 | 4.30 exact 4.24 |
| 3.73 | 3.91 exact 3.97 | 4.30 exact 4.21 | 4.56 exact 4.45 |
| 3.91 | 4.10 exact 4.16 | 4.30 exact 4.41 | 4.56 exact 4.67 |
| 4.10 | 4.30 exact 4.36 | 4.56 exact 4.63 | 4.88 exact 4.89 |
Exact = your ratio x new height / 31.0. Front and rear axles must match on a 4WD. Not every ratio is made for every axle. Want more pull than stock? Go one step shorter. More in the regearing guide.
Questions
What is 31x10.50R15 in metric?
787 mm tall and 267 mm wide on a 15-inch wheel.
How tall is a 31x10.50R15 tire?
31.0 inches on paper. Many inch-sized tires measure slightly under their label once mounted, so check the maker's spec sheet if it matters.
How many revolutions per mile does 31x10.50R15 do?
About 651 per mile (404 per km).
Nominal dimensions, calculated from the size marking. Real tires differ slightly by brand, rim width, pressure and wear. Fitment depends on your vehicle, lift and wheels: this page doesn't say whether a size fits. Updated 2026-11-14.