305/50R20 in inches & centimeters
Reference size: 305/50R20 has a nominal diameter of 32.01 inches and width of 12.01 inches, with a 6.00-inch sidewall on a 20-inch wheel.
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Nominal dimensions · 305/50R20
Side view
DOverall diameter32.01 in81.30 cm
SSidewall height6.00 in15.25 cm
WDWheel diameter20.00 in50.80 cm
Front view
DOverall diameter32.01 in81.30 cm
WSection width12.01 in30.50 cm
- DOverall diameter
- 32.01 in81.30 cm
- WSection width
- 12.01 in30.50 cm
- SSidewall height
- 6.00 in15.25 cm
- WDWheel diameter
- 20.00 in50.80 cm
- CCircumference
- 100.56 in255.41 cm
Approximate inch notation≈ 32.01 × 12.01R20
Diameter × width, with wheel diameter in inches, derived from the nominal size code. Use the tire maker’s catalog to choose an available product size.
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Wheels
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Nearby sizes
Compare these dimensions with the tire manufacturer’s published measurements and your vehicle’s tire and wheel specifications.
Detailed measurements and formulas for 305/50R20
Reference size: 305/50R20
| Measurement | inches | centimeters | millimeters |
|---|---|---|---|
| Overall diameter | 32.01 in | 81.30 cm | 813.0 mm |
| Section width | 12.01 in | 30.50 cm | 305.0 mm |
| Sidewall height | 6.00 in | 15.25 cm | 152.5 mm |
| Circumference | 100.56 in | 255.41 cm | 2,554.1 mm |
| Wheel diameter | 20.00 in | 50.80 cm | 508.0 mm |
| Revolutions / mi | 630.1 | ||
| Revolutions / km | 391.5 | ||
How we calculate it
305 = section width in millimeters; 50 = sidewall as a percentage of width; 20 = wheel diameter in inches.
Sidewall height: 305 × 50/100 = 152.5 mm
Overall diameter: (20 × 25.4) + (2 × 152.5) = 813 mm
Circumference: π × 813 ≈ 2,554.1 mm
Read the size-code guide Overall diameter: (20 × 25.4) + (2 × 152.5) = 813 mm
Circumference: π × 813 ≈ 2,554.1 mm
Reference model marked 245/40 ZR18 97Y.
Product image: Continental Tire
Tread-detail reference. Section width is calculated separately.
Product image: Continental TireWhat to check before changing size
Use the vehicle and tire specifications to check these three points:
- Vehicle placard and manual: match an approved size and the required load and speed ratings.
- Wheel specifications: check the tire maker’s wheel-width range and the wheel offset.
- Available space: check clearance at full steering lock and throughout suspension travel.
Method / data
Dimensions are calculated from the nominal size code. The reference catalog lists size codes; the tire maker’s specification sheet gives the exact model’s published measurements.
Calculation method and reference dataNearby sizes for 305/50R20
Sorted by nominal diameter difference. Compare the tire maker’s published dimensions for the sizes you shortlist.