245/50R18 tire size
245/50R18 is a metric size: 27.6" tall, 9.6" wide, on a 18" rim — about a 27.5x9.50R18. The sidewall is 4.8" and the tire turns 730 times per mile.
245/50R18 specs
| Overall diameter (height) | 27.65" · 702 mm |
|---|---|
| Section width | 9.65" · 245 mm |
| Sidewall height | 4.82" · 123 mm (50% of width) |
| Rim diameter | 18" |
| Circumference | 86.85" · 2.206 m |
| Revolutions per mile | 730 (453 per km) |
| Inch (flotation) equivalent | 27.5x9.50R18 |
Equivalent sizes on a 18" 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 | |
|---|---|---|---|---|---|
| 245/45R18 common | 26.68" | -3.49% | 0 mm | 57.9 mph | compare → |
| 235/50R18 common | 27.25" | -1.42% | -10 mm | 59.1 mph | compare → |
| 235/55R18 common | 28.18" | +1.92% | -10 mm | 61.2 mph | compare → |
| 235/45R18 common | 26.33" | -4.77% | -10 mm | 57.1 mph | compare → |
| 225/60R18 common | 28.63" | +3.56% | -20 mm | 62.1 mph | compare → |
| 225/50R18 common | 26.86" | -2.85% | -20 mm | 58.3 mph | compare → |
| 225/55R18 common | 27.74" | +0.36% | -20 mm | 60.2 mph | compare → |
| 255/45R18 common | 27.04" | -2.21% | +10 mm | 58.7 mph | compare → |
| 215/55R18 common | 27.31" | -1.21% | -30 mm | 59.3 mph | compare → |
| 275/40R18 common | 26.66" | -3.56% | +30 mm | 57.9 mph | compare → |
| 245/55R18 | 28.61" | +3.49% | 0 mm | 62.1 mph | compare → |
| 265/40R18 | 26.35" | -4.70% | +20 mm | 57.2 mph | compare → |
| 275/45R18 | 27.74" | +0.36% | +30 mm | 60.2 mph | compare → |
| 215/50R18 | 26.46" | -4.27% | -30 mm | 57.4 mph | compare → |
| 265/45R18 | 27.39" | -0.93% | +20 mm | 59.4 mph | compare → |
| 295/40R18 | 27.29" | -1.28% | +50 mm | 59.2 mph | compare → |
| 285/40R18 | 26.98" | -2.42% | +40 mm | 58.5 mph | calculate → |
| 345/35R18 | 27.51" | -0.50% | +100 mm | 59.7 mph | calculate → |
| 305/35R18 | 26.41" | -4.49% | +60 mm | 57.3 mph | calculate → |
| 295/45R18 | 28.45" | +2.92% | +50 mm | 61.8 mph | calculate → |
| 255/50R18 | 28.04" | +1.42% | +10 mm | 60.9 mph | calculate → |
| 315/40R18 | 27.92" | +1.00% | +70 mm | 60.6 mph | calculate → |
| 155/90R18 | 28.98" | +4.84% | -90 mm | 62.9 mph | calculate → |
| 305/40R18 | 27.61" | -0.14% | +60 mm | 59.9 mph | calculate → |
| 215/60R18 | 28.16" | +1.85% | -30 mm | 61.1 mph | calculate → |
| 155/85R18 | 28.37" | +2.63% | -90 mm | 61.6 mph | calculate → |
| 305/45R18 | 28.81" | +4.20% | +60 mm | 62.5 mph | calculate → |
| 145/85R18 | 27.70" | +0.21% | -100 mm | 60.1 mph | calculate → |
| 28x12.00R18 | 28.00" | +1.28% | +60 mm | 60.8 mph | calculate → |
| 285/45R18 | 28.10" | +1.64% | +40 mm | 61.0 mph | calculate → |
| 145/80R18 | 27.13" | -1.85% | -100 mm | 58.9 mph | calculate → |
| 165/70R18 | 27.09" | -1.99% | -80 mm | 58.8 mph | calculate → |
| 325/35R18 | 26.96" | -2.49% | +80 mm | 58.5 mph | calculate → |
| 155/70R18 | 26.54" | -3.99% | -90 mm | 57.6 mph | calculate → |
| 205/60R18 | 27.69" | +0.14% | -40 mm | 60.1 mph | calculate → |
| 28x10.00R18 | 28.00" | +1.28% | +9 mm | 60.8 mph | calculate → |
| 195/60R18 | 27.21" | -1.57% | -50 mm | 59.1 mph | calculate → |
| 265/50R18 | 28.43" | +2.85% | +20 mm | 61.7 mph | calculate → |
| 315/35R18 | 26.68" | -3.49% | +70 mm | 57.9 mph | calculate → |
Plus / minus sizing: 17" and 19" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 245/45R19 common | 27.68" | +0.13% | 0 mm | 60.1 mph | compare → |
| 225/60R17 common | 27.63" | -0.06% | -20 mm | 60.0 mph | compare → |
| 275/40R19 common | 27.66" | +0.06% | +30 mm | 60.0 mph | compare → |
| 245/55R17 | 27.61" | -0.13% | 0 mm | 59.9 mph | calculate → |
| 305/35R19 | 27.41" | -0.87% | +60 mm | 59.5 mph | calculate → |
| 155/70R19 | 27.54" | -0.37% | -90 mm | 59.8 mph | calculate → |
| 355/30R19 | 27.39" | -0.94% | +110 mm | 59.4 mph | calculate → |
| 305/45R17 | 27.81" | +0.58% | +60 mm | 60.4 mph | calculate → |
| 215/50R19 | 27.46" | -0.66% | -30 mm | 59.6 mph | calculate → |
| 165/80R17 | 27.39" | -0.91% | -80 mm | 59.5 mph | calculate → |
| 315/35R19 | 27.68" | +0.13% | +70 mm | 60.1 mph | calculate → |
| 275/50R17 | 27.83" | +0.66% | +30 mm | 60.4 mph | calculate → |
| 205/65R17 | 27.49" | -0.56% | -40 mm | 59.7 mph | calculate → |
| 225/50R19 | 27.86" | +0.77% | -20 mm | 60.5 mph | calculate → |
| 345/40R17 | 27.87" | +0.80% | +100 mm | 60.5 mph | calculate → |
Try another size against 245/50R18
Questions
What size is 245/50R18 in inches?
245/50R18 is about 27.6" tall and 9.6" wide on a 18-inch rim — roughly a 27.5x9.50R18 in inch sizing.
What does 245/50R18 mean?
245 mm section width, sidewall 50% of the width (4.82"), radial construction, 18-inch rim.
What tire sizes are equivalent to 245/50R18?
On the same 18" rim, within 3% of the diameter: 205/60R18 (+0.14%), 305/40R18 (-0.14%), 145/85R18 (+0.21%), 225/55R18 (+0.36%), 275/45R18 (+0.36%), 345/35R18 (-0.50%).
How many revolutions per mile does a 245/50R18 tire make?
About 730 revolutions per mile (circumference 86.9").
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.