ElpiAuto37X12.50R17 in metric
A 37X12.50R17 is 37.0″ (940 mm) tall and 12.50″ (318 mm) wide on a 17″ wheel. Converted directly it reads 320/80R17; the nearest standard metric size is 315/80R17.
Your tire size
e.g. 235/75R15, 33X12.50R15, or 225/45R17 91V
Metric equivalents of 37X12.50R17
315/80R17 is a near-exact match: −0.4% in height and −3 mm in width. The others trade a little height for width, or the reverse — all on the same 17″ wheel, within the ±3% most makers accept.
| Size | Diameter | Height vs 37X12.50R17 | Width vs 37X12.50R17 |
|---|---|---|---|
| 315/80R17 | 36.8″ · 936 mm | −0.4% | −3 mm |
| 325/80R17 | 37.5″ · 952 mm | +1.3% | +8 mm |
| 335/75R17 | 36.8″ · 934 mm | −0.6% | +18 mm |
| 305/85R17 | 37.4″ · 950 mm | +1.1% | −13 mm |
| 325/75R17 | 36.2″ · 919 mm | −2.2% | +8 mm |
37X12.50R17 dimensions
Computed from the size code; moulded tires vary by brand by roughly 1–3%.
| Dimension | Inches | Millimetres |
|---|---|---|
| Overall diameter | 37.0″ | 940 |
| Section width | 12.50″ | 318 |
| Sidewall height | 10.00″ | 254 |
| Circumference | 116.2″ | 2952 |
| Revolutions per mile | 545 | — |
| Revolutions per km | — | 339 |
The same height on other wheels
If you are changing wheel diameter but want to keep a 37.0″ overall height, these metric sizes come closest (within 2%).
| Wheel | Size | Diameter | Difference |
|---|---|---|---|
| 15″ | 325/85R15 | 36.8″ | −0.7% |
| 16″ | 315/85R16 | 37.1″ | +0.2% |
| 18″ | 345/70R18 | 37.0″ | +0.0% |
| 20″ | 335/65R20 | 37.1″ | +0.4% |
| 22″ | 345/55R22 | 36.9″ | −0.2% |
Wheel width and neighbouring sizes
A 318 mm-wide tire mounts on 9.5–12.0″ wide wheels (the usual approved range; the middle is ideal).
One step down is 35X12.50R17: −5.4% in diameter. With a speedometer calibrated for 37X12.50R17, an indicated 60 mph would be 56.8 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.