255/25R21 tire size in inches
A 255/25R21 tire measures
26.0" tall × 10.0" wide
2.51" sidewall on a 21" wheel. 775 revolutions per mile.
255/25R21 means a tire 255 mm wide, with sidewalls 25% as tall as the tire is wide (64 mm), radial construction (R), for a 21 inch wheel.
255/25R21 specs
| Overall diameter (height) | 26.02 inches (661 mm) |
|---|---|
| Section width | 10.04 inches (255 mm) |
| Sidewall height | 2.51 inches (64 mm) |
| Wheel (rim) diameter | 21 inches |
| Circumference | 81.7 inches (2,076 mm) |
| Revolutions per mile | 775 |
| Revolutions per kilometer | 482 |
| Approximate rim width | 8.5" to 10.0" |
| In inches (flotation style) | 26.0x10.0R21 |
| Aspect ratio | 25% |
Calculated from the size. Real tires differ by brand, model and tread depth, typically by a few tenths of an inch.
Sizes that can replace 255/25R21 on a 21" wheel
These 21" sizes are within 3% of 255/25R21's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 245/25R21 | 25.82" | 9.65" | −0.8% | 59.5 mph | Compare |
| 265/25R21 | 26.22" | 10.43" | +0.8% | 60.5 mph | Compare |
| 225/30R21 | 26.31" | 8.86" | +1.1% | 60.7 mph | Compare |
| 235/25R21 | 25.63" | 9.25" | −1.5% | 59.1 mph | Compare |
| 275/25R21 | 26.41" | 10.83" | +1.5% | 60.9 mph | Compare |
| 235/30R21 | 26.55" | 9.25" | +2.0% | 61.2 mph | Compare |
| 225/25R21 | 25.43" | 8.86" | −2.3% | 58.6 mph | Compare |
| 285/25R21 | 26.61" | 11.22" | +2.3% | 61.4 mph | Compare |
| 245/30R21 | 26.79" | 9.65" | +3.0% | 61.8 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 175/80R15 | 15" | 26.02" | 0.0% | Compare |
| 255/30R20 | 20" | 26.02" | 0.0% | Compare |
| 235/65R14 | 14" | 26.03" | 0.0% | Compare |
| 255/35R19 | 19" | 26.03" | 0.0% | Compare |
| 255/40R18 | 18" | 26.03" | 0.0% | Compare |
| 215/65R15 | 15" | 26.00" | −0.1% | Compare |
| 255/45R17 | 17" | 26.04" | +0.1% | Compare |
| 305/25R20 | 20" | 26.00" | −0.1% | Compare |
| 255/50R16 | 16" | 26.04" | +0.1% | Compare |
| 165/85R15 | 15" | 26.04" | +0.1% | Compare |
| 255/55R15 | 15" | 26.04" | +0.1% | Compare |
| 255/60R14 | 14" | 26.05" | +0.1% | Compare |
One size up or down
Compare 255/25R21 with another size
Questions
- How tall is a 255/25R21 tire?
- A 255/25R21 tire is 26.0 inches tall (661 mm), calculated from the size. It is 10.0 inches wide with 2.5 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 255/25R21 mean?
- 255/25R21 means a tire 255 mm wide, with sidewalls 25% as tall as the tire is wide (64 mm), radial construction (R), for a 21 inch wheel.
- How many revolutions per mile does a 255/25R21 tire make?
- About 775 revolutions per mile, based on a circumference of 81.7 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 255/25R21 tire?
- Roughly 8.5" to 10.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 245/25R21 instead of 255/25R21?
- 245/25R21 is −0.20 inches (−0.8%) in overall diameter, so at an indicated 60 mph you would be doing 59.5 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.