Start with the sidewall
Enter the full size printed on each tire. Prefixes P and LT are accepted; load and speed ratings are separate.
Compare tire sizes.See the difference.
Convert one size or compare two. Check dimensions, speedometer changes, wheel positions and nearby sizes in one place.
1.43% larger diameter
Ground clearance change+0.24 in+0.60 cm
Side view
Front view
A275/60R20
- Overall diameter
- 32.99 in83.80 cm
- Section width
- 10.83 in27.50 cm
- Sidewall height
- 6.50 in16.50 cm
- Wheel diameter
- 20.00 in50.80 cm
- Circumference
- 103.65 in263.27 cm
B285/60R20
- Overall diameter
- 33.46 in85.00 cm
- Section width
- 11.22 in28.50 cm
- Sidewall height
- 6.73 in17.10 cm
- Wheel diameter
- 20.00 in50.80 cm
- Circumference
- 105.13 in267.04 cm
Both tires shown at the same scale. Nominal dimensions. Photorealistic illustration; tread and wheel design are generic.
Swipe the table to see every measurement and change.
| Measurement | A · 275/60R20 | B · 285/60R20 | Change |
|---|---|---|---|
| Overall diameter | 32.99 in83.80 cm | 33.46 in85.00 cm | +0.47 in+1.20 cm |
| Section width | 10.83 in27.50 cm | 11.22 in28.50 cm | +0.39 in+1.00 cm |
| Sidewall height | 6.50 in16.50 cm | 6.73 in17.10 cm | +0.24 in+0.60 cm |
| Circumference | 103.65 in263.27 cm | 105.13 in267.04 cm | +1.48 in+3.77 cm |
| Wheel diameter | 20.00 in50.80 cm | 20.00 in50.80 cm | 0.00 in0.00 cm |
| Revolutions / mi | 611.3 | 602.7 | -8.6 |
Speedometer and distance
Assumes the speedometer was calibrated for the original tire. Real rolling circumference varies.
Estimated actual speed60.9 mphActual minus indicated: +0.9 mph
Actual speed change+1.43%
| Indicated speed (mph) | Estimated actual speed (mph) | Actual minus indicated (mph) |
|---|---|---|
| 20.0 | 20.3 | +0.3 |
| 30.0 | 30.4 | +0.4 |
| 40.0 | 40.6 | +0.6 |
| 50.0 | 50.7 | +0.7 |
| 60.0 | 60.9 | +0.9 |
| 70.0 | 71.0 | +1.0 |
| 80.0 | 81.1 | +1.1 |
| 90.0 | 91.3 | +1.3 |
Target speed, odometer and final-drive ratio
Required indicated speed59.2 mph
Estimated distance traveled101.4 mi
Uses the same original-tire calibration for the odometer. Distances are estimated from the nominal circumference ratio.
Enter the existing final-drive ratio to see the gearing change.
Uses the same transmission gear and nominal tire diameter. The restore value is a theoretical ratio to compare with available gearing.
Wheels
Enter wheel width, offset and spacer thickness for each setup.
Nearby sizes
Compare these dimensions with the tire manufacturer’s published measurements and your vehicle’s tire and wheel specifications.
Installed 275/60R20 115T tire shown as a reference.
Tread, sidewall and wheel examples
The size code gives the dimensions. These reference images show tread patterns, sidewall details and wheel designs.
Tread-detail reference. Section width is calculated separately.
Product image: Continental Tire
Reference image of a winter tread design.
Product image: Continental Tire
A fitted wheel showing spokes, brake disc and caliper.
From size code to dimensions
A tire code gives you enough information to calculate its nominal geometry. Actual manufacturer dimensions can differ.
Compare the measurements
Use the side and front views, dimension table and speedometer estimate to understand what changes.
Verify the fit
Check the vehicle placard, the tire maker’s wheel-width range and clearance as the steering and suspension move.
Featured tire size conversions
Go straight to dimensions in inches and centimeters, with a diagram and nearby sizes.
275/60R20Overall diameter32.99 in83.80 cm265/70R17Overall diameter31.61 in80.28 cm285/75R16Overall diameter32.83 in83.39 cm275/65R18Overall diameter32.07 in81.47 cm285/60R20Overall diameter33.46 in85.00 cm305/55R20Overall diameter33.21 in84.35 cm295/70R17Overall diameter33.26 in84.48 cm235/85R16Overall diameter31.73 in80.59 cm