245/40R15 tire size
245/40R15 is a metric size: 22.7" tall, 9.6" wide, on a 15" rim — about a 22.5x9.50R15. The sidewall is 3.9" and the tire turns 888 times per mile.
245/40R15 specs
| Overall diameter (height) | 22.72" · 577 mm |
|---|---|
| Section width | 9.65" · 245 mm |
| Sidewall height | 3.86" · 98 mm (40% of width) |
| Rim diameter | 15" |
| Circumference | 71.37" · 1.813 m |
| Revolutions per mile | 888 (552 per km) |
| Inch (flotation) equivalent | 22.5x9.50R15 |
Equivalent sizes on a 15" 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 | |
|---|---|---|---|---|---|
| 185/60R15 common | 23.74" | +4.51% | -60 mm | 62.7 mph | compare → |
| 205/50R15 | 23.07" | +1.56% | -40 mm | 60.9 mph | compare → |
| 185/55R15 | 23.01" | +1.30% | -60 mm | 60.8 mph | compare → |
| 195/55R15 | 23.44" | +3.21% | -50 mm | 61.9 mph | compare → |
| 195/50R15 | 22.68" | -0.17% | -50 mm | 59.9 mph | compare → |
| 225/45R15 | 22.97" | +1.13% | -20 mm | 60.7 mph | compare → |
| 175/55R15 | 22.58" | -0.61% | -70 mm | 59.6 mph | calculate → |
| 145/65R15 | 22.42" | -1.30% | -100 mm | 59.2 mph | calculate → |
| 155/60R15 | 22.32" | -1.73% | -90 mm | 59.0 mph | calculate → |
| 165/60R15 | 22.80" | +0.35% | -80 mm | 60.2 mph | calculate → |
| 275/35R15 | 22.58" | -0.61% | +30 mm | 59.6 mph | calculate → |
| 295/35R15 | 23.13" | +1.82% | +50 mm | 61.1 mph | calculate → |
| 195/45R15 | 21.91" | -3.55% | -50 mm | 57.9 mph | calculate → |
| 175/60R15 | 23.27" | +2.43% | -70 mm | 61.5 mph | calculate → |
| 22x8.00R15 | 22.00" | -3.15% | -42 mm | 58.1 mph | calculate → |
| 165/65R15 | 23.44" | +3.21% | -80 mm | 61.9 mph | calculate → |
| 215/50R15 | 23.46" | +3.29% | -30 mm | 62.0 mph | calculate → |
| 175/50R15 | 21.89" | -3.64% | -70 mm | 57.8 mph | calculate → |
Plus / minus sizing: 14" and 16" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 185/60R14 | 22.74" | +0.10% | -60 mm | 60.1 mph | compare → |
| 195/45R16 | 22.91" | +0.85% | -50 mm | 60.5 mph | calculate → |
| 205/55R14 | 22.88" | +0.71% | -40 mm | 60.4 mph | calculate → |
| 225/50R14 | 22.86" | +0.62% | -20 mm | 60.4 mph | calculate → |
| 215/40R16 | 22.77" | +0.24% | -30 mm | 60.1 mph | calculate → |
| 175/50R16 | 22.89" | +0.76% | -70 mm | 60.5 mph | calculate → |
Try another size against 245/40R15
Questions
What size is 245/40R15 in inches?
245/40R15 is about 22.7" tall and 9.6" wide on a 15-inch rim — roughly a 22.5x9.50R15 in inch sizing.
What does 245/40R15 mean?
245 mm section width, sidewall 40% of the width (3.86"), radial construction, 15-inch rim.
What tire sizes are equivalent to 245/40R15?
On the same 15" rim, within 3% of the diameter: 195/50R15 (-0.17%), 165/60R15 (+0.35%), 175/55R15 (-0.61%), 275/35R15 (-0.61%), 225/45R15 (+1.13%), 145/65R15 (-1.30%).
How many revolutions per mile does a 245/40R15 tire make?
About 888 revolutions per mile (circumference 71.4").
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.