275/55R20 Tire Size in Inches and Millimeters
Complete dimensional breakdown in inches and millimeters, approved wheel rim widths, vehicle fitments, speedometer error tables, and safe plus-sizing alternatives.
275/55R20 in Inches
275/55R20 converts to 31.91 inches tall and 10.83 inches wide, on a20 inch wheel. The sidewall accounts for 5.95 inches of that height, top and bottom.
- Overall height
- 31.91" (810.5 mm)
- Tread width
- 10.83" (275 mm)
- Sidewall height
- 5.95" (151.1 mm)
- Wheel diameter
- 20" (508.0 mm)
This size is also written 275/55/20 and 275-55-20. All three refer to the same tire: 275 mm wide, a sidewall 55% of that width, on a 20 inch rim.
275/55R20 Technical Dimension Table
Standardized measurements computed according to ETRTO & ISO 4000-1 passenger and commercial tire design formulas.
| Specification Property | Imperial (Inches / Miles) | Metric (Millimeters / Kilometers) |
|---|---|---|
| Overall Rolling Diameter | 31.91 in | 810.5 mm |
| Section Width (Cross-section) | 10.83 in | 275 mm |
| Sidewall Cushion Height | 5.95 in | 151.1 mm |
| Circumference (Rolling Distance) | 100.25 in | 2546.4 mm |
| Revolutions per Distance | 652 revs/mile | 405 revs/km |
| Wheel Rim Diameter | 20 in | 508.0 mm |
| Approved Rim Width Range | 7.4" – 9.6" | 188 – 244 mm |
| Measuring / Ideal Rim Width | 8.5 in | 216 mm |
| Aspect Ratio (Profile %) | 55% of section width | |
What 275/55R20 Is Typically Used For
Dimensions in this range are typical of pickups, SUVs and off-road fitments, where load capacity and sidewall strength matter more than steering response.
To find the size your specific vehicle takes, check the placard on the driver-side door jamb or your owner's manual. Fitment depends on model year, trim, brake caliper clearance, wheel offset and suspension setup, so the correct size for your car is the one the manufacturer specifies.
Safe Alternative Sizes for 275/55R20 (±3% Rule)
These tire sizes stay within 3% of the 31.91" original diameter, keeping speedometer error minimal and preventing ABS/traction control faults.
Popular Comparisons with 275/55R20
Frequently Asked Questions about 275/55R20
What size is 275/55R20 in inches?
The 275/55R20 tire measures approximately 31.91" in overall diameter, 10.83" in section width (tread/sidewall cross-section), and is mounted on a 20" diameter wheel rim. The same size is often written 275/55/20 or 275-55-20.
What rim width is recommended for 275/55R20?
The approved rim width range for 275/55R20 is 7.4" to 9.6" wide, with an ideal measuring rim width of 8.5" for optimal tread contact and even wear.
What are the closest safe alternative sizes for 275/55R20?
The closest safe tire sizes within the industry standard ±3% diameter limit include 225/70R19.5. These sizes maintain accurate speedometer calibration and clearance.
How many revolutions per mile does 275/55R20 make?
A standard 275/55R20 tire rotates approximately 652 revolutions per mile (405 revs per kilometer) at normal inflation pressure and rolling radius.