275/25R21 tire size
275/25R21 is a metric size: 26.4" tall, 10.8" wide, on a 21" rim — about a 26.5x11.00R21. The sidewall is 2.7" and the tire turns 764 times per mile.
275/25R21 specs
| Overall diameter (height) | 26.41" · 671 mm |
|---|---|
| Section width | 10.83" · 275 mm |
| Sidewall height | 2.71" · 69 mm (25% of width) |
| Rim diameter | 21" |
| Circumference | 82.98" · 2.108 m |
| Revolutions per mile | 764 (474 per km) |
| Inch (flotation) equivalent | 26.5x11.00R21 |
Equivalent sizes on a 21" rim
Sizes within ±5% of the overall diameter. Green rows are inside the usual ±3% limit for keeping the speedometer, ABS and gearing right; red rows are bigger changes that need clearance checks.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 285/30R21 | 27.73" | +4.99% | +10 mm | 63.0 mph | calculate → |
| 275/30R21 | 27.50" | +4.10% | 0 mm | 62.5 mph | calculate → |
| 255/30R21 | 27.02" | +2.31% | -20 mm | 61.4 mph | calculate → |
| 295/25R21 | 26.81" | +1.49% | +20 mm | 60.9 mph | calculate → |
| 265/30R21 | 27.26" | +3.20% | -10 mm | 61.9 mph | calculate → |
| 305/25R21 | 27.00" | +2.24% | +30 mm | 61.3 mph | calculate → |
| 325/25R21 | 27.40" | +3.73% | +50 mm | 62.2 mph | calculate → |
| 245/30R21 | 26.79" | +1.42% | -30 mm | 60.8 mph | calculate → |
| 275/20R21 | 25.33" | -4.10% | 0 mm | 57.5 mph | calculate → |
Plus / minus sizing: 20" and 22" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 275/30R20 common | 26.50" | +0.31% | 0 mm | 60.2 mph | calculate → |
| 235/35R20 | 26.48" | +0.24% | -40 mm | 60.1 mph | calculate → |
| 265/30R20 | 26.26" | -0.58% | -10 mm | 59.7 mph | calculate → |
| 225/35R20 | 26.20" | -0.80% | -50 mm | 59.5 mph | calculate → |
| 335/25R20 | 26.59" | +0.69% | +60 mm | 60.4 mph | calculate → |
| 325/25R20 | 26.40" | -0.06% | +50 mm | 60.0 mph | calculate → |
| 315/25R20 | 26.20" | -0.80% | +40 mm | 59.5 mph | calculate → |
Try another size against 275/25R21
Questions
What size is 275/25R21 in inches?
275/25R21 is about 26.4" tall and 10.8" wide on a 21-inch rim — roughly a 26.5x11.00R21 in inch sizing.
What does 275/25R21 mean?
275 mm section width, sidewall 25% of the width (2.71"), radial construction, 21-inch rim.
What tire sizes are equivalent to 275/25R21?
On the same 21" rim, within 3% of the diameter: 245/30R21 (+1.42%), 295/25R21 (+1.49%), 305/25R21 (+2.24%), 255/30R21 (+2.31%), 265/30R21 (+3.20%), 325/25R21 (+3.73%).
How many revolutions per mile does a 275/25R21 tire make?
About 764 revolutions per mile (circumference 83.0").
How these numbers are computed
Diameter = rim + 2 × sidewall, sidewall = width × aspect ÷ 100, circumference = π × diameter, revolutions per mile = 63,360 ÷ circumference. Real tires differ by brand by a few tenths of an inch. Last reviewed October 14, 2026.