325/35R20 vs 225/45R21 tire size
225/45R21 vs 325/35R20, diameter
Same diameter
- Speedometer
- 60.0 mph
- At a true 60 mph
- Diameter
- 28.97 in
- Was 28.96 in
- Revs per mile
- 696
- Was 696
- 3% guideline
- Within
Car built for 325/35R20, now on 225/45R21.
325/35R20 and 225/45R21
| Measure | 325/35R20 | 225/45R21 | Difference |
|---|---|---|---|
| Width, mm | 325 | 225 | -100 |
| Sidewall, % of width | 35 | 45 | +10 |
| Rim, in | 20 | 21 | +1 |
| Section height, in | 4.48 | 3.99 | -0.49 |
| Diameter, in | 28.96 | 28.97 | +0.02 (+0.1%) |
| Circumference, in | 91.0 | 91.0 | +0.0 |
| Revs per mile | 696 | 696 | -0 (-0.1%) |
Fitting 225/45R21 instead of 325/35R20
Within the usual 3% diameter guideline.
- Needs 21 in wheels.
Cars with 325/35R20
Cars with 225/45R21
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