ElpiAuto30X9.50R15 in metric
A 30X9.50R15 is 30.0″ (762 mm) tall and 9.50″ (241 mm) wide on a 15″ wheel. Converted directly it reads 240/80R15; the nearest standard metric size is 235/80R15.
Your tire size
e.g. 235/75R15, 33X12.50R15, or 225/45R17 91V
Metric equivalents of 30X9.50R15
No standard metric size lands exactly on 30X9.50R15. The best compromise is 235/80R15 (−0.7% height, −6 mm width); the list is ranked by height and width together, all on a 15″ wheel within ±3%.
| Size | Diameter | Height vs 30X9.50R15 | Width vs 30X9.50R15 |
|---|---|---|---|
| 235/80R15 | 29.8″ · 757 mm | −0.7% | −6 mm |
| 255/75R15 | 30.1″ · 764 mm | +0.2% | +14 mm |
| 245/80R15 | 30.4″ · 773 mm | +1.4% | +4 mm |
| 225/85R15 | 30.1″ · 764 mm | +0.2% | −16 mm |
| 245/75R15 | 29.5″ · 749 mm | −1.8% | +4 mm |
30X9.50R15 dimensions
Computed from the size code; moulded tires vary by brand by roughly 1–3%.
| Dimension | Inches | Millimetres |
|---|---|---|
| Overall diameter | 30.0″ | 762 |
| Section width | 9.50″ | 241 |
| Sidewall height | 7.50″ | 191 |
| Circumference | 94.2″ | 2394 |
| Revolutions per mile | 672 | — |
| Revolutions per km | — | 418 |
The same height on other wheels
If you are changing wheel diameter but want to keep a 30.0″ overall height, these metric sizes come closest (within 2%).
| Wheel | Size | Diameter | Difference |
|---|---|---|---|
| 16″ | 255/70R16 | 30.1″ | +0.2% |
| 17″ | 235/70R17 | 30.0″ | −0.2% |
| 18″ | 235/65R18 | 30.0″ | +0.1% |
| 20″ | 255/50R20 | 30.0″ | +0.1% |
Wheel width and neighbouring sizes
A 241 mm-wide tire mounts on 6.5–9.0″ wide wheels (the usual approved range; the middle is ideal).
One step down is 235/75R15: −3.7% in diameter. With a speedometer calibrated for 30X9.50R15, an indicated 60 mph would be 57.8 mph on 235/75R15.
One step up is 31X10.50R15: +3.3% in diameter. With a speedometer calibrated for 30X9.50R15, an indicated 60 mph would be 62.0 mph on 31X10.50R15.
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.