245/40R17 tire size
245/40R17 is a metric size: 24.7" tall, 9.6" wide, on a 17" rim — about a 24.5x9.50R17. The sidewall is 3.9" and the tire turns 816 times per mile.
245/40R17 specs
| Overall diameter (height) | 24.72" · 628 mm |
|---|---|
| Section width | 9.65" · 245 mm |
| Sidewall height | 3.86" · 98 mm (40% of width) |
| Rim diameter | 17" |
| Circumference | 77.65" · 1.972 m |
| Revolutions per mile | 816 (507 per km) |
| Inch (flotation) equivalent | 24.5x9.50R17 |
Equivalent sizes on a 17" 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 | |
|---|---|---|---|---|---|
| 225/45R17 common | 24.97" | +1.04% | -20 mm | 60.6 mph | compare → |
| 225/50R17 common | 25.86" | +4.62% | -20 mm | 62.8 mph | compare → |
| 215/45R17 common | 24.62" | -0.40% | -30 mm | 59.8 mph | compare → |
| 205/50R17 common | 25.07" | +1.43% | -40 mm | 60.9 mph | compare → |
| 215/50R17 common | 25.46" | +3.03% | -30 mm | 61.8 mph | compare → |
| 235/45R17 common | 25.33" | +2.47% | -10 mm | 61.5 mph | compare → |
| 245/45R17 common | 25.68" | +3.90% | 0 mm | 62.3 mph | compare → |
| 205/45R17 common | 24.26" | -1.83% | -40 mm | 58.9 mph | compare → |
| 255/40R17 common | 25.03" | +1.27% | +10 mm | 60.8 mph | compare → |
| 205/55R17 | 25.88" | +4.70% | -40 mm | 62.8 mph | compare → |
| 275/40R17 | 25.66" | +3.82% | +30 mm | 62.3 mph | compare → |
| 235/40R17 | 24.40" | -1.27% | -10 mm | 59.2 mph | compare → |
| 215/40R17 | 23.77" | -3.82% | -30 mm | 57.7 mph | compare → |
| 315/35R17 | 25.68" | +3.90% | +70 mm | 62.3 mph | compare → |
| 275/35R17 | 24.58" | -0.56% | +30 mm | 59.7 mph | calculate → |
| 225/40R17 | 24.09" | -2.55% | -20 mm | 58.5 mph | calculate → |
| 265/40R17 | 25.35" | +2.55% | +20 mm | 61.5 mph | calculate → |
| 155/70R17 | 25.54" | +3.35% | -90 mm | 62.0 mph | calculate → |
| 295/35R17 | 25.13" | +1.67% | +50 mm | 61.0 mph | calculate → |
| 195/45R17 | 23.91" | -3.27% | -50 mm | 58.0 mph | calculate → |
| 145/70R17 | 24.99" | +1.12% | -100 mm | 60.7 mph | calculate → |
| 245/35R17 | 23.75" | -3.90% | 0 mm | 57.7 mph | calculate → |
| 185/60R17 | 25.74" | +4.14% | -60 mm | 62.5 mph | calculate → |
Plus / minus sizing: 16" and 18" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 205/55R16 common | 24.88" | +0.65% | -40 mm | 60.4 mph | compare → |
| 245/35R18 common | 24.75" | +0.14% | 0 mm | 60.1 mph | compare → |
| 225/50R16 common | 24.86" | +0.57% | -20 mm | 60.3 mph | compare → |
| 215/40R18 | 24.77" | +0.22% | -30 mm | 60.1 mph | compare → |
| 285/30R18 | 24.73" | +0.06% | +40 mm | 60.0 mph | compare → |
| 245/45R16 | 24.68" | -0.14% | 0 mm | 59.9 mph | compare → |
| 185/60R16 | 24.74" | +0.10% | -60 mm | 60.1 mph | calculate → |
| 235/35R18 | 24.48" | -0.97% | -10 mm | 59.4 mph | calculate → |
Try another size against 245/40R17
Questions
What size is 245/40R17 in inches?
245/40R17 is about 24.7" tall and 9.6" wide on a 17-inch rim — roughly a 24.5x9.50R17 in inch sizing.
What does 245/40R17 mean?
245 mm section width, sidewall 40% of the width (3.86"), radial construction, 17-inch rim.
What tire sizes are equivalent to 245/40R17?
On the same 17" rim, within 3% of the diameter: 215/45R17 (-0.40%), 275/35R17 (-0.56%), 225/45R17 (+1.04%), 145/70R17 (+1.12%), 235/40R17 (-1.27%), 255/40R17 (+1.27%).
How many revolutions per mile does a 245/40R17 tire make?
About 816 revolutions per mile (circumference 77.6").
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.