Tire Ruler245/50R20 dimensions
| Overall diameter (height) | 29.65″ · 753 mm |
| Section width | 9.65″ · 245 mm |
| Sidewall height | 4.82″ · 123 mm |
| Wheel diameter | 20″ |
| Rim width (rule of thumb) | 7–8.5″ |
| Circumference | 93.1″ |
| Revolutions per mile | 680 |
| In inches (flotation style) | 29.6 × 9.6R20 |
How it’s calculated: the sidewall is 50% of the 245 mm width = 122.5 mm (4.82″). Add two sidewalls to the 20″ wheel: 20 + 2 × 4.82 = 29.65″.
Bigger tires than 245/50R20 on 20″ wheels
| Size | Height | Taller by | 60 mph reads |
|---|---|---|---|
| 255/50R20 | 30.0″ | +0.39″ (+1.3%) | 60.8 mph |
| 265/50R20 | 30.4″ | +0.79″ (+2.7%) | 61.6 mph |
| 275/50R20 | 30.8″ | +1.18″ (+4.0%) | 62.4 mph |
| 255/55R20 | 31.0″ | +1.40″ (+4.7%) | 62.8 mph |
| 285/50R20 | 31.2″ | +1.57″ (+5.3%) | 63.2 mph |
“60 mph reads” is your real speed when a speedometer set up for 245/50R20 shows 60. Above about 3% taller, most trucks need a leveling kit or lift, and the speedometer should be recalibrated.
Sizes equivalent to 245/50R20
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 |
|---|---|---|---|
| 275/45R20 | 29.7″ | 10.8″ | +0.3% |
| 265/45R20 | 29.4″ | 10.4″ | −0.9% |
| 255/50R20 | 30.0″ | 10.0″ | +1.3% |
Same height on a different wheel size
Changing wheel size (plus or minus sizing) while keeping the overall height keeps your speedometer right:
- 30x9.50R15: 30.0″ tall on a 15″ wheel (+1.2%)
- 235/75R16: 29.9″ tall on a 16″ wheel (+0.8%)
- 225/75R16: 29.3″ tall on a 16″ wheel (−1.2%)
- 245/70R16: 29.5″ tall on a 16″ wheel (−0.5%)
- 255/70R16: 30.1″ tall on a 16″ wheel (+1.4%)
- 245/65R17: 29.5″ tall on a 17″ wheel (−0.4%)
- 255/65R17: 30.1″ tall on a 17″ wheel (+1.4%)
- 235/70R17: 30.0″ tall on a 17″ wheel (+1.0%)
- 245/60R18: 29.6″ tall on an 18″ wheel (−0.2%)
- 235/65R18: 30.0″ tall on an 18″ wheel (+1.3%)
- 255/55R19: 30.0″ tall on a 19″ wheel (+1.3%)
- 245/55R19: 29.6″ tall on a 19″ wheel (−0.1%)
Popular 245/50R20 comparisons
Frequently asked questions
Is 245/50R20 a 30 inch tire?
Not quite. 245/50R20 is 29.65 inches tall, between a 29 and a 30 inch tire.
What size is 245/50R20 in inches?
245/50R20 is 29.6 inches tall (overall diameter), 9.6 inches wide, with a 4.8 inch sidewall, and fits a 20 inch wheel.
What tire size is equivalent to 245/50R20?
Sizes within 1.5% of the same diameter on a 20" wheel: 275/45R20 (29.7"), 265/45R20 (29.4"), 255/50R20 (30.0"). Check load index and width before swapping.
What rim width fits 245/50R20?
As a rule of thumb, about 7–8.5 inches. The tire maker's spec sheet lists the approved range for each model.
How many revolutions per mile does 245/50R20 make?
About 680 revolutions per mile in theory (circumference 93.1 in). Real tires turn slightly more because they flatten under load.