275/50R21 tire size
275/50R21 is a metric size: 31.8" tall, 10.8" wide, on a 21" rim — about a 32x11.00R21. The sidewall is 5.4" and the tire turns 634 times per mile.
275/50R21 specs
| Overall diameter (height) | 31.83" · 808 mm |
|---|---|
| Section width | 10.83" · 275 mm |
| Sidewall height | 5.41" · 138 mm (50% of width) |
| Rim diameter | 21" |
| Circumference | 99.99" · 2.540 m |
| Revolutions per mile | 634 (394 per km) |
| Inch (flotation) equivalent | 32x11.00R21 |
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 | |
|---|---|---|---|---|---|
| 275/45R21 | 30.74" | -3.40% | 0 mm | 58.0 mph | compare → |
| 285/45R21 | 31.10" | -2.29% | +10 mm | 58.6 mph | compare → |
| 295/40R21 | 30.29" | -4.82% | +20 mm | 57.1 mph | compare → |
| 265/45R21 | 30.39" | -4.52% | -10 mm | 57.3 mph | compare → |
| 315/40R21 | 30.92" | -2.85% | +40 mm | 58.3 mph | compare → |
| 255/50R21 | 31.04" | -2.47% | -20 mm | 58.5 mph | compare → |
| 235/50R21 | 30.25" | -4.95% | -40 mm | 57.0 mph | calculate → |
| 315/45R21 | 32.16" | +1.05% | +40 mm | 60.6 mph | calculate → |
| 325/40R21 | 31.24" | -1.86% | +50 mm | 58.9 mph | calculate → |
| 275/55R21 | 32.91" | +3.40% | 0 mm | 62.0 mph | calculate → |
| 305/40R21 | 30.61" | -3.83% | +30 mm | 57.7 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 | |
|---|---|---|---|---|---|
| 275/55R20 common | 31.91" | +0.26% | 0 mm | 60.2 mph | compare → |
| 285/45R22 common | 32.10" | +0.85% | +10 mm | 60.5 mph | compare → |
| 245/60R20 | 31.57" | -0.79% | -30 mm | 59.5 mph | compare → |
| 305/50R20 | 32.01" | +0.57% | +30 mm | 60.3 mph | compare → |
| 275/45R22 | 31.74" | -0.26% | 0 mm | 59.8 mph | compare → |
| 305/40R22 | 31.61" | -0.69% | +30 mm | 59.6 mph | compare → |
| 255/60R20 | 32.05" | +0.69% | -20 mm | 60.4 mph | compare → |
| 295/50R20 | 31.61" | -0.67% | +20 mm | 59.6 mph | calculate → |
Try another size against 275/50R21
Questions
What size is 275/50R21 in inches?
275/50R21 is about 31.8" tall and 10.8" wide on a 21-inch rim — roughly a 32x11.00R21 in inch sizing.
What does 275/50R21 mean?
275 mm section width, sidewall 50% of the width (5.41"), radial construction, 21-inch rim.
What tire sizes are equivalent to 275/50R21?
On the same 21" rim, within 3% of the diameter: 315/45R21 (+1.05%), 325/40R21 (-1.86%), 285/45R21 (-2.29%), 255/50R21 (-2.47%), 315/40R21 (-2.85%), 275/45R21 (-3.40%).
How many revolutions per mile does a 275/50R21 tire make?
About 634 revolutions per mile (circumference 100.0").
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.