ST205/90R15 — what does it mean?
- ST means "special trailer"
- 205 stands for tread width in millimeters
- 90 is an aspect ration between the tread width and the sidewall in percents
- R means that the tire has a radial construction
- 15 is a wheel diameter (or rim) in inches
How to convert ST205 90R15 to inches?
First of all, we need to divide 205 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 8.1″. Then, 90% of the 8.1″ will result in 7.3″ sidewall.
To get the total height or tire diameter, we need to sum the 15″ rim diameter with two of the sidewall heights. It will result in a 29.6″ total tire diameter (or height).
For your convenience, below is a table for ST205/90R15 conversion to inches:
| Inches | Metric | |
|---|---|---|
| Overall diameter (height) | 29.6″ | 752 mm |
| Tread width | 8.1″ | 205 mm |
| Wheel diameter | 15″ | 752 mm |
| Sidewall height | 7.3″ | 185 mm |
| Circumference | 92.9″ | 2361 mm |
| Revolutions | 682 / ml | 424 / km |
Alternatives to a ST205/90R15 tire
If you're looking to upsize your ST205 90R15 tires, try to stay within 3% deviation of an overall diameter for safety reasons.
| Tire | Tire diameter | Width | Wheel Size |
|---|---|---|---|
| 235/75R15 | 28.8″ -0.67% | 9.3″ | 15″ |
| LT235/75R15 | 28.8″ -0.67% | 9.3″ | 15″ |
| 265/70R15 | 29.6″ 0% | 10.4″ | 15″ |
| 255/70R15 | 29″ -0.5% | 10″ | 15″ |
| 255/75R15 | 30″ 0.33% | 10″ | 15″ |
| 245/75R15 | 29.4″ -0.17% | 9.6″ | 15″ |
| 205/90R15 | 29.6″ 0% | 8.1″ | 15″ |
| 215/85R15 | 29.4″ -0.17% | 8.5″ | 15″ |
| 225/80R15 | 29.2″ -0.33% | 8.9″ | 15″ |
| 235/80R15 | 29.8″ 0.17% | 9.3″ | 15″ |