185R15 tire size
185R15 is a metric size: 26.9" tall, 7.3" wide, on a 15" rim — about a 27x7.50R15. The sidewall is 6.0" and the tire turns 748 times per mile.
185R15 specs
| Overall diameter (height) | 26.94" · 684 mm |
|---|---|
| Section width | 7.28" · 185 mm |
| Sidewall height | 5.97" · 152 mm (82% of width) |
| Rim diameter | 15" |
| Circumference | 84.65" · 2.150 m |
| Revolutions per mile | 748 (465 per km) |
| Inch (flotation) equivalent | 27x7.50R15 |
Equivalent sizes on a 15" 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 | |
|---|---|---|---|---|---|
| 215/70R15 | 26.85" | -0.35% | +30 mm | 59.8 mph | calculate → |
| 205/70R15 | 26.30" | -2.40% | +20 mm | 58.6 mph | calculate → |
| 225/70R15 | 27.40" | +1.69% | +40 mm | 61.0 mph | calculate → |
| 215/75R15 | 27.70" | +2.79% | +30 mm | 61.7 mph | calculate → |
| 225/75R15 | 28.29" | +4.98% | +40 mm | 63.0 mph | calculate → |
| 215/65R15 | 26.00" | -3.49% | +30 mm | 57.9 mph | calculate → |
| 205/75R15 | 27.11" | +0.60% | +20 mm | 60.4 mph | calculate → |
| 235/70R15 | 27.95" | +3.74% | +50 mm | 62.2 mph | calculate → |
| 275/60R15 | 27.99" | +3.89% | +90 mm | 62.3 mph | calculate → |
| 255/60R15 | 27.05" | +0.38% | +70 mm | 60.2 mph | calculate → |
| 235/60R15 | 26.10" | -3.13% | +50 mm | 58.1 mph | calculate → |
| 275/50R15 | 25.83" | -4.15% | +90 mm | 57.5 mph | calculate → |
| 195/70R15 | 25.75" | -4.44% | +10 mm | 57.3 mph | calculate → |
| 295/50R15 | 26.61" | -1.23% | +110 mm | 59.3 mph | calculate → |
| 245/60R15 | 26.57" | -1.37% | +60 mm | 59.2 mph | calculate → |
| 225/60R15 | 25.63" | -4.88% | +40 mm | 57.1 mph | calculate → |
| 325/50R15 | 27.80" | +3.16% | +140 mm | 61.9 mph | calculate → |
| 26x10.00R15 | 26.00" | -3.51% | +69 mm | 57.9 mph | calculate → |
| 295/55R15 | 27.78" | +3.08% | +110 mm | 61.8 mph | calculate → |
| 26x8.50R15 | 26.00" | -3.51% | +31 mm | 57.9 mph | calculate → |
| 28x10.50R15 | 28.00" | +3.92% | +82 mm | 62.3 mph | calculate → |
| 28x11.50R15 | 28.00" | +3.92% | +107 mm | 62.3 mph | calculate → |
| 28x9.00R15 | 28.00" | +3.92% | +44 mm | 62.3 mph | calculate → |
| 27x9.50R15 | 27.00" | +0.20% | +56 mm | 60.1 mph | calculate → |
| 26x10.50R15 | 26.00" | -3.51% | +82 mm | 57.9 mph | calculate → |
| 26x12.00R15 | 26.00" | -3.51% | +120 mm | 57.9 mph | calculate → |
| 26x6.00R15 | 26.00" | -3.51% | -33 mm | 57.9 mph | calculate → |
| 26x7.50R15 | 26.00" | -3.51% | +6 mm | 57.9 mph | calculate → |
| 26x8.00R15 | 26.00" | -3.51% | +18 mm | 57.9 mph | calculate → |
| 28x10.00R15 | 28.00" | +3.92% | +69 mm | 62.3 mph | calculate → |
| 28x12.00R15 | 28.00" | +3.92% | +120 mm | 62.3 mph | calculate → |
| 28x6.00R15 | 28.00" | +3.92% | -33 mm | 62.3 mph | calculate → |
| 28x7.50R15 | 28.00" | +3.92% | +6 mm | 62.3 mph | calculate → |
| 27x10.50R15 | 27.00" | +0.20% | +82 mm | 60.1 mph | calculate → |
| 235/65R15 | 27.03" | +0.31% | +50 mm | 60.2 mph | calculate → |
| 26x11.50R15 | 26.00" | -3.51% | +107 mm | 57.9 mph | calculate → |
| 28x12.50R15 | 28.00" | +3.92% | +133 mm | 62.3 mph | calculate → |
| 28x13.50R15 | 28.00" | +3.92% | +158 mm | 62.3 mph | calculate → |
| 255/65R15 | 28.05" | +4.11% | +70 mm | 62.5 mph | calculate → |
| 165R15 | 25.65" | -4.79% | -20 mm | 57.1 mph | calculate → |
Plus / minus sizing: 14" and 16" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 215/65R16 common | 27.00" | +0.22% | +30 mm | 60.1 mph | calculate → |
| 235/60R16 common | 27.10" | +0.58% | +50 mm | 60.4 mph | calculate → |
| 215/75R14 | 26.70" | -0.92% | +30 mm | 59.4 mph | calculate → |
| 155/90R16 | 26.98" | +0.15% | -30 mm | 60.1 mph | calculate → |
| 27x11.00R14 | 27.00" | +0.20% | +94 mm | 60.1 mph | calculate → |
| 27x8.50R14 | 27.00" | +0.20% | +31 mm | 60.1 mph | calculate → |
| 27x9.50R14 | 27.00" | +0.20% | +56 mm | 60.1 mph | calculate → |
| 27x9.00R14 | 27.00" | +0.20% | +44 mm | 60.1 mph | calculate → |
| 355/40R16 | 27.18" | +0.88% | +170 mm | 60.5 mph | calculate → |
Try another size against 185R15
Questions
What size is 185R15 in inches?
185R15 is about 26.9" tall and 7.3" wide on a 15-inch rim — roughly a 27x7.50R15 in inch sizing.
What does 185R15 mean?
185 mm section width, sidewall 82% of the width (5.97"), radial construction, 15-inch rim.
What tire sizes are equivalent to 185R15?
On the same 15" rim, within 3% of the diameter: 27x10.50R15 (+0.20%), 27x9.50R15 (+0.20%), 235/65R15 (+0.31%), 215/70R15 (-0.35%), 255/60R15 (+0.38%), 205/75R15 (+0.60%).
How many revolutions per mile does a 185R15 tire make?
About 748 revolutions per mile (circumference 84.6").
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.