255/40R19 tire size
255/40R19 is a metric size: 27.0" tall, 10.0" wide, on a 19" rim — about a 27x10.00R19. The sidewall is 4.0" and the tire turns 746 times per mile.
255/40R19 specs
| Overall diameter (height) | 27.03" · 687 mm |
|---|---|
| Section width | 10.04" · 255 mm |
| Sidewall height | 4.02" · 102 mm (40% of width) |
| Rim diameter | 19" |
| Circumference | 84.92" · 2.157 m |
| Revolutions per mile | 746 (464 per km) |
| Inch (flotation) equivalent | 27x10.00R19 |
Equivalent sizes on a 19" 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 | |
|---|---|---|---|---|---|
| 245/45R19 common | 27.68" | +2.40% | -10 mm | 61.4 mph | compare → |
| 245/40R19 common | 26.72" | -1.17% | -10 mm | 59.3 mph | compare → |
| 235/40R19 common | 26.40" | -2.33% | -20 mm | 58.6 mph | compare → |
| 255/35R19 common | 26.03" | -3.71% | 0 mm | 57.8 mph | compare → |
| 255/45R19 common | 28.04" | +3.71% | 0 mm | 62.2 mph | compare → |
| 275/35R19 common | 26.58" | -1.67% | +20 mm | 59.0 mph | compare → |
| 275/40R19 common | 27.66" | +2.33% | +20 mm | 61.4 mph | compare → |
| 245/35R19 common | 25.75" | -4.73% | -10 mm | 57.2 mph | compare → |
| 225/40R19 common | 26.09" | -3.50% | -30 mm | 57.9 mph | compare → |
| 225/45R19 common | 26.97" | -0.22% | -30 mm | 59.9 mph | compare → |
| 235/50R19 common | 28.25" | +4.52% | -20 mm | 62.7 mph | compare → |
| 285/35R19 common | 26.85" | -0.66% | +30 mm | 59.6 mph | compare → |
| 235/45R19 common | 27.33" | +1.09% | -20 mm | 60.7 mph | compare → |
| 265/35R19 common | 26.30" | -2.69% | +10 mm | 58.4 mph | compare → |
| 285/30R19 | 25.73" | -4.81% | +30 mm | 57.1 mph | compare → |
| 305/30R19 | 26.20" | -3.06% | +50 mm | 58.2 mph | compare → |
| 285/40R19 | 27.98" | +3.50% | +30 mm | 62.1 mph | compare → |
| 295/30R19 | 25.97" | -3.93% | +40 mm | 57.6 mph | compare → |
| 265/40R19 | 27.35" | +1.17% | +10 mm | 60.7 mph | compare → |
| 325/30R19 | 26.68" | -1.31% | +70 mm | 59.2 mph | compare → |
| 295/35R19 | 27.13" | +0.36% | +40 mm | 60.2 mph | compare → |
| 345/30R19 | 27.15" | +0.44% | +90 mm | 60.3 mph | compare → |
| 315/30R19 | 26.44" | -2.18% | +60 mm | 58.7 mph | compare → |
| 295/40R19 | 28.29" | +4.66% | +40 mm | 62.8 mph | compare → |
| 305/35R19 | 27.41" | +1.38% | +50 mm | 60.8 mph | calculate → |
| 155/70R19 | 27.54" | +1.89% | -100 mm | 61.1 mph | calculate → |
| 355/30R19 | 27.39" | +1.31% | +100 mm | 60.8 mph | calculate → |
| 215/50R19 | 27.46" | +1.60% | -40 mm | 61.0 mph | calculate → |
| 175/60R19 | 27.27" | +0.87% | -80 mm | 60.5 mph | calculate → |
| 195/50R19 | 26.68" | -1.31% | -60 mm | 59.2 mph | calculate → |
| 335/30R19 | 26.91" | -0.44% | +80 mm | 59.7 mph | calculate → |
| 315/35R19 | 27.68" | +2.40% | +60 mm | 61.4 mph | calculate → |
| 225/50R19 | 27.86" | +3.06% | -30 mm | 61.8 mph | calculate → |
| 145/80R19 | 28.13" | +4.08% | -110 mm | 62.4 mph | calculate → |
Plus / minus sizing: 18" and 20" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 235/50R18 common | 27.25" | +0.82% | -20 mm | 60.5 mph | compare → |
| 225/50R18 common | 26.86" | -0.64% | -30 mm | 59.6 mph | compare → |
| 255/35R20 common | 27.03" | -0.01% | 0 mm | 60.0 mph | compare → |
| 255/45R18 common | 27.04" | +0.01% | 0 mm | 60.0 mph | compare → |
| 295/30R20 | 26.97" | -0.23% | +40 mm | 59.9 mph | compare → |
| 305/30R20 | 27.20" | +0.64% | +50 mm | 60.4 mph | compare → |
| 295/40R18 | 27.29" | +0.96% | +40 mm | 60.6 mph | compare → |
| 285/40R18 | 26.98" | -0.20% | +30 mm | 59.9 mph | calculate → |
| 345/25R20 | 26.79" | -0.89% | +90 mm | 59.5 mph | calculate → |
| 225/40R20 | 27.09" | +0.20% | -30 mm | 60.1 mph | calculate → |
| 165/70R18 | 27.09" | +0.23% | -90 mm | 60.1 mph | calculate → |
| 325/35R18 | 26.96" | -0.28% | +70 mm | 59.8 mph | calculate → |
| 145/80R18 | 27.13" | +0.38% | -110 mm | 60.2 mph | calculate → |
| 145/60R20 | 26.85" | -0.67% | -110 mm | 59.6 mph | calculate → |
| 195/60R18 | 27.21" | +0.67% | -60 mm | 60.4 mph | calculate → |
Try another size against 255/40R19
Questions
What size is 255/40R19 in inches?
255/40R19 is about 27.0" tall and 10.0" wide on a 19-inch rim — roughly a 27x10.00R19 in inch sizing.
What does 255/40R19 mean?
255 mm section width, sidewall 40% of the width (4.02"), radial construction, 19-inch rim.
What tire sizes are equivalent to 255/40R19?
On the same 19" rim, within 3% of the diameter: 225/45R19 (-0.22%), 295/35R19 (+0.36%), 335/30R19 (-0.44%), 345/30R19 (+0.44%), 285/35R19 (-0.66%), 175/60R19 (+0.87%).
How many revolutions per mile does a 255/40R19 tire make?
About 746 revolutions per mile (circumference 84.9").
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.