Tire Ruler325/60R20 dimensions
| Overall diameter (height) | 35.35″ · 898 mm |
| Section width | 12.80″ · 325 mm |
| Sidewall height | 7.68″ · 195 mm |
| Wheel diameter | 20″ |
| Rim width (rule of thumb) | 9–11.5″ |
| Circumference | 111.1″ |
| Revolutions per mile | 570 |
| In inches (flotation style) | 35.4 × 12.8R20 |
How it’s calculated: the sidewall is 60% of the 325 mm width = 195.0 mm (7.68″). Add two sidewalls to the 20″ wheel: 20 + 2 × 7.68 = 35.35″.
Bigger tires than 325/60R20 on 20″ wheels
| Size | Height | Taller by | 60 mph reads |
|---|---|---|---|
| 37x12.50R20 | 37.0″ | +1.65″ (+4.7%) | 62.8 mph |
“60 mph reads” is your real speed when a speedometer set up for 325/60R20 shows 60. Above about 3% taller, most trucks need a leveling kit or lift, and the speedometer should be recalibrated.
Sizes equivalent to 325/60R20
Within 1.5% of the same height on a 20″ wheel. Usually interchangeable for the speedometer; check width, load index and clearance.
| Size | Height | Width | Difference |
|---|---|---|---|
| 295/65R20 | 35.1″ | 11.6″ | −0.7% |
| 35x12.50R20 | 35.0″ | 12.5″ | −1.0% |
| 35x13.50R20 | 35.0″ | 13.5″ | −1.0% |
Same height on a different wheel size
Changing wheel size (plus or minus sizing) while keeping the overall height keeps your speedometer right:
- 35x12.50R15: 35.0″ tall on a 15″ wheel (−1.0%)
- 35x12.50R17: 35.0″ tall on a 17″ wheel (−1.0%)
- 285/75R18: 34.8″ tall on an 18″ wheel (−1.5%)
- 35x12.50R18: 35.0″ tall on an 18″ wheel (−1.0%)
- 35x12.50R22: 35.0″ tall on a 22″ wheel (−1.0%)
Frequently asked questions
Is 325/60R20 a 35 inch tire?
Not quite. 325/60R20 is 35.35 inches tall, between a 35 and a 36 inch tire.
What size is 325/60R20 in inches?
325/60R20 is 35.4 inches tall (overall diameter), 12.8 inches wide, with a 7.7 inch sidewall, and fits a 20 inch wheel.
What tire size is equivalent to 325/60R20?
Sizes within 1.5% of the same diameter on a 20" wheel: 295/65R20 (35.1"), 35x12.50R20 (35.0"), 35x13.50R20 (35.0"). Check load index and width before swapping.
What rim width fits 325/60R20?
As a rule of thumb, about 9–11.5 inches. The tire maker's spec sheet lists the approved range for each model.
How many revolutions per mile does 325/60R20 make?
About 570 revolutions per mile in theory (circumference 111.1 in). Real tires turn slightly more because they flatten under load.