235/30R21 — what does it mean?
- 235 stands for tread width in millimeters
- 30 is an aspect ration between the tread width and the sidewall in percents
- R means that the tire has a radial construction
- 21 is a wheel diameter (or rim) in inches
How to convert 235 30R21 to inches?
First of all, we need to divide 235 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 9.3″. Then, 30% of the 9.3″ will result in 2.8″ sidewall.
To get the total height or tire diameter, we need to sum the 21″ rim diameter with two of the sidewall heights. It will result in a 26.6″ total tire diameter (or height).
For your convenience, below is a table for 235/30R21 conversion to inches:
| Inches | Metric | |
|---|---|---|
| Overall diameter (height) | 26.6″ | 676 mm |
| Tread width | 9.3″ | 235 mm |
| Wheel diameter | 21″ | 676 mm |
| Sidewall height | 2.8″ | 71 mm |
| Circumference | 83.5″ | 2123 mm |
| Revolutions | 758 / ml | 471 / km |
Alternatives to a 235/30R21 tire
If you're looking to upsize your 235 30R21 tires, try to stay within 3% deviation of an overall diameter for safety reasons.
| Tire | Tire diameter | Width | Wheel Size |
|---|---|---|---|
| 245/30R21 | 26.8″ 0.18% | 9.6″ | 21″ |
| 255/30R21 | 27″ 0.37% | 10″ | 21″ |
| 265/30R21 | 27.2″ 0.55% | 10.4″ | 21″ |
| 275/25R21 | 26.4″ -0.19% | 10.8″ | 21″ |
| 295/25R21 | 26.8″ 0.18% | 11.6″ | 21″ |
| 305/25R21 | 27″ 0.37% | 12″ | 21″ |
| 325/25R21 | 27.4″ 0.73% | 12.8″ | 21″ |
| 375/20R21 | 27″ 0.37% | 14.8″ | 21″ |