355/25R21 — what does it mean?
- 355 stands for tread width in millimeters
- 25 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 355 25R21 to inches?
First of all, we need to divide 355 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 14″. Then, 25% of the 14″ will result in 3.5″ 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 28″ total tire diameter (or height).
For your convenience, below is a table for 355/25R21 conversion to inches:
| Inches | Metric | |
|---|---|---|
| Overall diameter (height) | 28″ | 711 mm |
| Tread width | 14″ | 355 mm |
| Wheel diameter | 21″ | 711 mm |
| Sidewall height | 3.5″ | 89 mm |
| Circumference | 87.9″ | 2233 mm |
| Revolutions | 721 / ml | 448 / km |
Alternatives to a 355/25R21 tire
If you're looking to upsize your 355 25R21 tires, try to stay within 3% deviation of an overall diameter for safety reasons.
| Tire | Tire diameter | Width | Wheel Size |
|---|---|---|---|
| 235/35R21 | 27.4″ -0.53% | 9.3″ | 21″ |
| 245/35R21 | 27.8″ -0.18% | 9.6″ | 21″ |
| 245/40R21 | 28.8″ 0.73% | 9.6″ | 21″ |
| 255/35R21 | 28″ 0% | 10″ | 21″ |
| 265/30R21 | 27.2″ -0.71% | 10.4″ | 21″ |
| 265/35R21 | 28.4″ 0.35% | 10.4″ | 21″ |
| 275/30R21 | 27.6″ -0.35% | 10.8″ | 21″ |
| 275/35R21 | 28.6″ 0.52% | 10.8″ | 21″ |
| 285/30R21 | 27.8″ -0.18% | 11.2″ | 21″ |
| 295/30R21 | 28″ 0% | 11.6″ | 21″ |