315/25R20 tire size
315/25R20 is a metric size: 26.2" tall, 12.4" wide, on a 20" rim — about a 26x12.50R20. The sidewall is 3.1" and the tire turns 770 times per mile.
315/25R20 specs
| Overall diameter (height) | 26.20" · 666 mm |
|---|---|
| Section width | 12.40" · 315 mm |
| Sidewall height | 3.10" · 79 mm (25% of width) |
| Rim diameter | 20" |
| Circumference | 82.31" · 2.091 m |
| Revolutions per mile | 770 (478 per km) |
| Inch (flotation) equivalent | 26x12.50R20 |
Equivalent sizes on a 20" 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 | |
|---|---|---|---|---|---|
| 245/35R20 common | 26.75" | +2.10% | -70 mm | 61.3 mph | calculate → |
| 255/35R20 common | 27.03" | +3.16% | -60 mm | 61.9 mph | calculate → |
| 285/30R20 common | 26.73" | +2.03% | -30 mm | 61.2 mph | calculate → |
| 275/30R20 common | 26.50" | +1.13% | -40 mm | 60.7 mph | calculate → |
| 265/35R20 common | 27.30" | +4.21% | -50 mm | 62.5 mph | calculate → |
| 235/35R20 | 26.48" | +1.05% | -80 mm | 60.6 mph | calculate → |
| 295/30R20 | 26.97" | +2.93% | -20 mm | 61.8 mph | calculate → |
| 305/30R20 | 27.20" | +3.83% | -10 mm | 62.3 mph | calculate → |
| 245/30R20 | 25.79" | -1.58% | -70 mm | 59.1 mph | calculate → |
| 265/30R20 | 26.26" | +0.23% | -50 mm | 60.1 mph | calculate → |
| 255/30R20 | 26.02" | -0.68% | -60 mm | 59.6 mph | calculate → |
| 225/35R20 | 26.20" | 0.00% | -90 mm | 60.0 mph | calculate → |
| 335/25R20 | 26.59" | +1.50% | +20 mm | 60.9 mph | calculate → |
| 315/30R20 | 27.44" | +4.73% | 0 mm | 62.8 mph | calculate → |
| 235/30R20 | 25.55" | -2.48% | -80 mm | 58.5 mph | calculate → |
| 305/25R20 | 26.00" | -0.75% | -10 mm | 59.5 mph | calculate → |
| 235/40R20 | 27.40" | +4.58% | -80 mm | 62.7 mph | calculate → |
| 295/25R20 | 25.81" | -1.50% | -20 mm | 59.1 mph | calculate → |
| 325/25R20 | 26.40" | +0.75% | +10 mm | 60.5 mph | calculate → |
| 285/25R20 | 25.61" | -2.25% | -30 mm | 58.6 mph | calculate → |
| 345/25R20 | 26.79" | +2.25% | +30 mm | 61.4 mph | calculate → |
| 225/30R20 | 25.31" | -3.38% | -90 mm | 58.0 mph | calculate → |
| 225/40R20 | 27.09" | +3.38% | -90 mm | 62.0 mph | calculate → |
| 145/60R20 | 26.85" | +2.48% | -170 mm | 61.5 mph | calculate → |
| 275/25R20 | 25.41" | -3.01% | -40 mm | 58.2 mph | calculate → |
| 155/60R20 | 27.32" | +4.28% | -160 mm | 62.6 mph | calculate → |
| 145/65R20 | 27.42" | +4.66% | -170 mm | 62.8 mph | calculate → |
| 215/30R20 | 25.08" | -4.28% | -100 mm | 57.4 mph | calculate → |
Plus / minus sizing: 19" and 21" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 235/40R19 common | 26.40" | +0.77% | -80 mm | 60.5 mph | calculate → |
| 255/35R19 common | 26.03" | -0.66% | -60 mm | 59.6 mph | calculate → |
| 225/40R19 common | 26.09" | -0.44% | -90 mm | 59.7 mph | calculate → |
| 265/35R19 common | 26.30" | +0.39% | -50 mm | 60.2 mph | calculate → |
| 305/30R19 | 26.20" | +0.02% | -10 mm | 60.0 mph | calculate → |
| 295/30R19 | 25.97" | -0.89% | -20 mm | 59.5 mph | calculate → |
| 315/30R19 | 26.44" | +0.92% | 0 mm | 60.5 mph | calculate → |
| 275/25R21 | 26.41" | +0.81% | -40 mm | 60.5 mph | calculate → |
Try another size against 315/25R20
Questions
What size is 315/25R20 in inches?
315/25R20 is about 26.2" tall and 12.4" wide on a 20-inch rim — roughly a 26x12.50R20 in inch sizing.
What does 315/25R20 mean?
315 mm section width, sidewall 25% of the width (3.10"), radial construction, 20-inch rim.
What tire sizes are equivalent to 315/25R20?
On the same 20" rim, within 3% of the diameter: 225/35R20 (0.00%), 265/30R20 (+0.23%), 255/30R20 (-0.68%), 305/25R20 (-0.75%), 325/25R20 (+0.75%), 235/35R20 (+1.05%).
How many revolutions per mile does a 315/25R20 tire make?
About 770 revolutions per mile (circumference 82.3").
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.