225/50R18 tire size
225/50R18 is a metric size: 26.9" tall, 8.9" wide, on a 18" rim — about a 27x9.00R18. The sidewall is 4.4" and the tire turns 751 times per mile.
225/50R18 specs
| Overall diameter (height) | 26.86" · 682 mm |
|---|---|
| Section width | 8.86" · 225 mm |
| Sidewall height | 4.43" · 113 mm (50% of width) |
| Rim diameter | 18" |
| Circumference | 84.38" · 2.143 m |
| Revolutions per mile | 751 (467 per km) |
| Inch (flotation) equivalent | 27x9.00R18 |
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 | |
|---|---|---|---|---|---|
| 225/45R18 common | 25.97" | -3.30% | 0 mm | 58.0 mph | compare → |
| 245/40R18 common | 25.72" | -4.25% | +20 mm | 57.4 mph | compare → |
| 245/45R18 common | 26.68" | -0.66% | +20 mm | 59.6 mph | compare → |
| 235/50R18 common | 27.25" | +1.47% | +10 mm | 60.9 mph | compare → |
| 235/45R18 common | 26.33" | -1.98% | +10 mm | 58.8 mph | compare → |
| 235/55R18 common | 28.18" | +4.91% | +10 mm | 62.9 mph | compare → |
| 225/55R18 common | 27.74" | +3.30% | 0 mm | 62.0 mph | compare → |
| 255/40R18 common | 26.03" | -3.08% | +30 mm | 58.2 mph | compare → |
| 245/50R18 common | 27.65" | +2.93% | +20 mm | 61.8 mph | compare → |
| 275/35R18 common | 25.58" | -4.76% | +50 mm | 57.1 mph | compare → |
| 255/45R18 common | 27.04" | +0.66% | +30 mm | 60.4 mph | compare → |
| 215/55R18 common | 27.31" | +1.69% | -10 mm | 61.0 mph | compare → |
| 275/40R18 common | 26.66" | -0.73% | +50 mm | 59.6 mph | compare → |
| 215/45R18 common | 25.62" | -4.62% | -10 mm | 57.2 mph | compare → |
| 265/40R18 | 26.35" | -1.91% | +40 mm | 58.9 mph | compare → |
| 285/35R18 | 25.85" | -3.74% | +60 mm | 57.8 mph | compare → |
| 295/35R18 | 26.13" | -2.71% | +70 mm | 58.4 mph | compare → |
| 335/30R18 | 25.91" | -3.52% | +110 mm | 57.9 mph | compare → |
| 275/45R18 | 27.74" | +3.30% | +50 mm | 62.0 mph | compare → |
| 215/50R18 | 26.46" | -1.47% | -10 mm | 59.1 mph | compare → |
| 295/40R18 | 27.29" | +1.61% | +70 mm | 61.0 mph | compare → |
| 265/45R18 | 27.39" | +1.98% | +40 mm | 61.2 mph | compare → |
| 285/40R18 | 26.98" | +0.44% | +60 mm | 60.3 mph | calculate → |
| 305/35R18 | 26.41" | -1.69% | +80 mm | 59.0 mph | calculate → |
| 345/35R18 | 27.51" | +2.42% | +120 mm | 61.5 mph | calculate → |
| 255/50R18 | 28.04" | +4.40% | +30 mm | 62.6 mph | calculate → |
| 315/40R18 | 27.92" | +3.96% | +90 mm | 62.4 mph | calculate → |
| 305/40R18 | 27.61" | +2.79% | +80 mm | 61.7 mph | calculate → |
| 215/60R18 | 28.16" | +4.84% | -10 mm | 62.9 mph | calculate → |
| 325/35R18 | 26.96" | +0.37% | +100 mm | 60.2 mph | calculate → |
| 165/70R18 | 27.09" | +0.88% | -60 mm | 60.5 mph | calculate → |
| 145/80R18 | 27.13" | +1.03% | -80 mm | 60.6 mph | calculate → |
| 155/70R18 | 26.54" | -1.17% | -70 mm | 59.3 mph | calculate → |
| 145/85R18 | 27.70" | +3.15% | -80 mm | 61.9 mph | calculate → |
| 26x12.00R18 | 26.00" | -3.20% | +80 mm | 58.1 mph | calculate → |
| 26x6.00R18 | 26.00" | -3.20% | -73 mm | 58.1 mph | calculate → |
| 26x8.00R18 | 26.00" | -3.20% | -22 mm | 58.1 mph | calculate → |
| 145/70R18 | 25.99" | -3.22% | -80 mm | 58.1 mph | calculate → |
| 28x12.00R18 | 28.00" | +4.25% | +80 mm | 62.6 mph | calculate → |
| 285/45R18 | 28.10" | +4.62% | +60 mm | 62.8 mph | calculate → |
| 315/35R18 | 26.68" | -0.66% | +90 mm | 59.6 mph | calculate → |
| 195/60R18 | 27.21" | +1.32% | -30 mm | 60.8 mph | calculate → |
| 345/30R18 | 26.15" | -2.64% | +120 mm | 58.4 mph | calculate → |
| 205/60R18 | 27.69" | +3.08% | -20 mm | 61.8 mph | calculate → |
| 28x10.00R18 | 28.00" | +4.25% | +29 mm | 62.6 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 | |
|---|---|---|---|---|---|
| 225/55R17 common | 26.74" | -0.43% | 0 mm | 59.7 mph | compare → |
| 245/40R19 common | 26.72" | -0.53% | +20 mm | 59.7 mph | compare → |
| 255/40R19 common | 27.03" | +0.64% | +30 mm | 60.4 mph | compare → |
| 225/45R19 common | 26.97" | +0.43% | 0 mm | 60.3 mph | compare → |
| 285/35R19 common | 26.85" | -0.01% | +60 mm | 60.0 mph | compare → |
| 325/30R19 | 26.68" | -0.67% | +100 mm | 59.6 mph | compare → |
| 245/50R17 | 26.65" | -0.79% | +20 mm | 59.5 mph | compare → |
| 255/50R17 | 27.04" | +0.67% | +30 mm | 60.4 mph | calculate → |
| 155/80R17 | 26.76" | -0.35% | -70 mm | 59.8 mph | calculate → |
| 195/50R19 | 26.68" | -0.67% | -30 mm | 59.6 mph | calculate → |
| 335/30R19 | 26.91" | +0.21% | +110 mm | 60.1 mph | calculate → |
| 205/60R17 | 26.69" | -0.64% | -20 mm | 59.6 mph | calculate → |
Try another size against 225/50R18
Questions
What size is 225/50R18 in inches?
225/50R18 is about 26.9" tall and 8.9" wide on a 18-inch rim — roughly a 27x9.00R18 in inch sizing.
What does 225/50R18 mean?
225 mm section width, sidewall 50% of the width (4.43"), radial construction, 18-inch rim.
What tire sizes are equivalent to 225/50R18?
On the same 18" rim, within 3% of the diameter: 325/35R18 (+0.37%), 285/40R18 (+0.44%), 245/45R18 (-0.66%), 255/45R18 (+0.66%), 315/35R18 (-0.66%), 275/40R18 (-0.73%).
How many revolutions per mile does a 225/50R18 tire make?
About 751 revolutions per mile (circumference 84.4").
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.