245/60R20 vs 275/50R21 tire size
275/50R21 vs 245/60R20, diameter
+0.8% taller
- Speedometer
- 59.5 mph
- At a true 60 mph
- Diameter
- 31.83 in
- Was 31.57 in
- Revs per mile
- 634
- Was 639
- 3% guideline
- Within
Car built for 245/60R20, now on 275/50R21.
245/60R20 and 275/50R21
| Measure | 245/60R20 | 275/50R21 | Difference |
|---|---|---|---|
| Width, mm | 245 | 275 | +30 |
| Sidewall, % of width | 60 | 50 | -10 |
| Rim, in | 20 | 21 | +1 |
| Section height, in | 5.79 | 5.41 | -0.37 |
| Diameter, in | 31.57 | 31.83 | +0.25 (+0.8%) |
| Circumference, in | 99.2 | 100.0 | +0.8 |
| Revs per mile | 639 | 634 | -5 (-0.8%) |
Fitting 275/50R21 instead of 245/60R20
Within the usual 3% diameter guideline.
- Needs 21 in wheels.
- 30 mm wider. Check rubbing at full lock.
Cars with 245/60R20
Cars with 275/50R21
What this cannot tell you
Diameter within 3% is a common shop guideline, not a maker spec.
Load index, offset and clearance are not in this data.
- Two or more sources agree
- One source
- Model-level or estimate
- Sources differ