295/40R21 tire size
295/40R21 is a metric size: 30.3" tall, 11.6" wide, on a 21" rim — about a 30.5x11.50R21. The sidewall is 4.6" and the tire turns 666 times per mile.
295/40R21 specs
| Overall diameter (height) | 30.29" · 769 mm |
|---|---|
| Section width | 11.61" · 295 mm |
| Sidewall height | 4.65" · 118 mm (40% of width) |
| Rim diameter | 21" |
| Circumference | 95.16" · 2.417 m |
| Revolutions per mile | 666 (414 per km) |
| Inch (flotation) equivalent | 30.5x11.50R21 |
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 | |
|---|---|---|---|---|---|
| 265/40R21 common | 29.35" | -3.12% | -30 mm | 58.1 mph | compare → |
| 295/35R21 | 29.13" | -3.83% | 0 mm | 57.7 mph | compare → |
| 275/45R21 | 30.74" | +1.49% | -20 mm | 60.9 mph | compare → |
| 255/40R21 | 29.03" | -4.16% | -40 mm | 57.5 mph | compare → |
| 285/45R21 | 31.10" | +2.66% | -10 mm | 61.6 mph | compare → |
| 265/45R21 | 30.39" | +0.32% | -30 mm | 60.2 mph | compare → |
| 285/40R21 | 29.98" | -1.04% | -10 mm | 59.4 mph | compare → |
| 275/40R21 | 29.66" | -2.08% | -20 mm | 58.8 mph | compare → |
| 285/35R21 | 28.85" | -4.74% | -10 mm | 57.2 mph | compare → |
| 315/35R21 | 29.68" | -2.01% | +20 mm | 58.8 mph | compare → |
| 315/40R21 | 30.92" | +2.08% | +20 mm | 61.2 mph | compare → |
| 255/45R21 | 30.04" | -0.84% | -40 mm | 59.5 mph | compare → |
| 245/45R21 | 29.68" | -2.01% | -50 mm | 58.8 mph | compare → |
| 255/50R21 | 31.04" | +2.47% | -40 mm | 61.5 mph | compare → |
| 235/50R21 | 30.25" | -0.13% | -60 mm | 59.9 mph | calculate → |
| 235/45R21 | 29.33" | -3.18% | -60 mm | 58.1 mph | calculate → |
| 305/35R21 | 29.41" | -2.92% | +10 mm | 58.2 mph | calculate → |
| 335/30R21 | 28.91" | -4.55% | +40 mm | 57.3 mph | calculate → |
| 345/30R21 | 29.15" | -3.77% | +50 mm | 57.7 mph | calculate → |
| 225/45R21 | 28.97" | -4.35% | -70 mm | 57.4 mph | calculate → |
| 305/40R21 | 30.61" | +1.04% | +10 mm | 60.6 mph | calculate → |
| 325/40R21 | 31.24" | +3.12% | +30 mm | 61.9 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 | |
|---|---|---|---|---|---|
| 255/50R20 common | 30.04" | -0.83% | -40 mm | 59.5 mph | compare → |
| 265/50R20 common | 30.43" | +0.47% | -30 mm | 60.3 mph | compare → |
| 235/55R20 common | 30.18" | -0.38% | -60 mm | 59.8 mph | compare → |
| 265/40R22 | 30.35" | +0.18% | -30 mm | 60.1 mph | compare → |
| 285/45R20 | 30.10" | -0.64% | -10 mm | 59.6 mph | compare → |
| 295/45R20 | 30.45" | +0.53% | 0 mm | 60.3 mph | compare → |
| 295/35R22 | 30.13" | -0.53% | 0 mm | 59.7 mph | compare → |
| 255/40R22 | 30.03" | -0.86% | -40 mm | 59.5 mph | compare → |
| 305/35R22 | 30.41" | +0.38% | +10 mm | 60.2 mph | calculate → |
Try another size against 295/40R21
Questions
What size is 295/40R21 in inches?
295/40R21 is about 30.3" tall and 11.6" wide on a 21-inch rim — roughly a 30.5x11.50R21 in inch sizing.
What does 295/40R21 mean?
295 mm section width, sidewall 40% of the width (4.65"), radial construction, 21-inch rim.
What tire sizes are equivalent to 295/40R21?
On the same 21" rim, within 3% of the diameter: 235/50R21 (-0.13%), 265/45R21 (+0.32%), 255/45R21 (-0.84%), 305/40R21 (+1.04%), 285/40R21 (-1.04%), 275/45R21 (+1.49%).
How many revolutions per mile does a 295/40R21 tire make?
About 666 revolutions per mile (circumference 95.2").
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.