255/40R17 tire size
255/40R17 is a metric size: 25.0" tall, 10.0" wide, on a 17" rim — about a 25x10.00R17. The sidewall is 4.0" and the tire turns 806 times per mile.
255/40R17 specs
| Overall diameter (height) | 25.03" · 636 mm |
|---|---|
| Section width | 10.04" · 255 mm |
| Sidewall height | 4.02" · 102 mm (40% of width) |
| Rim diameter | 17" |
| Circumference | 78.64" · 1.997 m |
| Revolutions per mile | 806 (501 per km) |
| Inch (flotation) equivalent | 25x10.00R17 |
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" | -0.24% | -30 mm | 59.9 mph | compare → |
| 225/50R17 common | 25.86" | +3.30% | -30 mm | 62.0 mph | compare → |
| 215/45R17 common | 24.62" | -1.65% | -40 mm | 59.0 mph | compare → |
| 205/50R17 common | 25.07" | +0.16% | -50 mm | 60.1 mph | compare → |
| 215/50R17 common | 25.46" | +1.73% | -40 mm | 61.0 mph | compare → |
| 235/45R17 common | 25.33" | +1.18% | -20 mm | 60.7 mph | compare → |
| 245/45R17 common | 25.68" | +2.60% | -10 mm | 61.6 mph | compare → |
| 245/40R17 common | 24.72" | -1.26% | -10 mm | 59.2 mph | compare → |
| 205/45R17 common | 24.26" | -3.07% | -50 mm | 58.2 mph | compare → |
| 235/50R17 common | 26.25" | +4.88% | -20 mm | 62.9 mph | compare → |
| 205/55R17 | 25.88" | +3.38% | -50 mm | 62.0 mph | compare → |
| 275/40R17 | 25.66" | +2.52% | +20 mm | 61.5 mph | compare → |
| 235/40R17 | 24.40" | -2.52% | -20 mm | 58.5 mph | compare → |
| 255/45R17 | 26.04" | +4.01% | 0 mm | 62.4 mph | compare → |
| 315/35R17 | 25.68" | +2.60% | +60 mm | 61.6 mph | compare → |
| 275/35R17 | 24.58" | -1.81% | +20 mm | 58.9 mph | calculate → |
| 335/35R17 | 26.23" | +4.80% | +80 mm | 62.9 mph | calculate → |
| 265/40R17 | 25.35" | +1.26% | +10 mm | 60.8 mph | calculate → |
| 155/70R17 | 25.54" | +2.04% | -100 mm | 61.2 mph | calculate → |
| 225/40R17 | 24.09" | -3.77% | -30 mm | 57.7 mph | calculate → |
| 285/40R17 | 25.98" | +3.77% | +30 mm | 62.3 mph | calculate → |
| 195/60R17 | 26.21" | +4.72% | -60 mm | 62.8 mph | calculate → |
| 295/35R17 | 25.13" | +0.39% | +40 mm | 60.2 mph | calculate → |
| 175/65R17 | 25.96" | +3.70% | -80 mm | 62.2 mph | calculate → |
| 145/80R17 | 26.13" | +4.40% | -110 mm | 62.6 mph | calculate → |
| 195/45R17 | 23.91" | -4.48% | -60 mm | 57.3 mph | calculate → |
| 145/70R17 | 24.99" | -0.16% | -110 mm | 59.9 mph | calculate → |
| 185/60R17 | 25.74" | +2.83% | -70 mm | 61.7 mph | calculate → |
| 26x6.00R17 | 26.00" | +3.87% | -103 mm | 62.3 mph | calculate → |
| 165/70R17 | 26.09" | +4.25% | -90 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 | |
|---|---|---|---|---|---|
| 225/40R18 common | 25.09" | +0.22% | -30 mm | 60.1 mph | compare → |
| 205/55R16 common | 24.88" | -0.61% | -50 mm | 59.6 mph | compare → |
| 255/35R18 common | 25.03" | -0.02% | 0 mm | 60.0 mph | compare → |
| 225/50R16 common | 24.86" | -0.69% | -30 mm | 59.6 mph | compare → |
| 295/30R18 | 24.97" | -0.25% | +40 mm | 59.8 mph | compare → |
| 195/60R16 | 25.21" | +0.72% | -60 mm | 60.4 mph | calculate → |
| 305/30R18 | 25.20" | +0.69% | +50 mm | 60.4 mph | calculate → |
| 145/80R16 | 25.13" | +0.41% | -110 mm | 60.2 mph | calculate → |
| 205/45R18 | 25.26" | +0.93% | -50 mm | 60.6 mph | calculate → |
Try another size against 255/40R17
Questions
What size is 255/40R17 in inches?
255/40R17 is about 25.0" tall and 10.0" wide on a 17-inch rim — roughly a 25x10.00R17 in inch sizing.
What does 255/40R17 mean?
255 mm section width, sidewall 40% of the width (4.02"), radial construction, 17-inch rim.
What tire sizes are equivalent to 255/40R17?
On the same 17" rim, within 3% of the diameter: 145/70R17 (-0.16%), 205/50R17 (+0.16%), 225/45R17 (-0.24%), 295/35R17 (+0.39%), 235/45R17 (+1.18%), 245/40R17 (-1.26%).
How many revolutions per mile does a 255/40R17 tire make?
About 806 revolutions per mile (circumference 78.6").
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.