185/55R15 tire size
185/55R15 is a metric size: 23.0" tall, 7.3" wide, on a 15" rim — about a 23x7.50R15. The sidewall is 4.0" and the tire turns 876 times per mile.
185/55R15 specs
| Overall diameter (height) | 23.01" · 585 mm |
|---|---|
| Section width | 7.28" · 185 mm |
| Sidewall height | 4.01" · 102 mm (55% of width) |
| Rim diameter | 15" |
| Circumference | 72.29" · 1.836 m |
| Revolutions per mile | 876 (545 per km) |
| Inch (flotation) equivalent | 23x7.50R15 |
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 | |
|---|---|---|---|---|---|
| 185/60R15 common | 23.74" | +3.17% | 0 mm | 61.9 mph | compare → |
| 175/65R15 | 23.96" | +4.11% | -10 mm | 62.5 mph | compare → |
| 205/50R15 | 23.07" | +0.26% | +20 mm | 60.2 mph | compare → |
| 195/55R15 | 23.44" | +1.88% | +10 mm | 61.1 mph | compare → |
| 225/45R15 | 22.97" | -0.17% | +40 mm | 59.9 mph | compare → |
| 195/50R15 | 22.68" | -1.45% | +10 mm | 59.1 mph | compare → |
| 225/50R15 | 23.86" | +3.68% | +40 mm | 62.2 mph | compare → |
| 245/40R15 | 22.72" | -1.28% | +60 mm | 59.2 mph | compare → |
| 175/55R15 | 22.58" | -1.88% | -10 mm | 58.9 mph | calculate → |
| 145/65R15 | 22.42" | -2.57% | -40 mm | 58.5 mph | calculate → |
| 155/60R15 | 22.32" | -2.99% | -30 mm | 58.2 mph | calculate → |
| 295/35R15 | 23.13" | +0.51% | +110 mm | 60.3 mph | calculate → |
| 165/60R15 | 22.80" | -0.94% | -20 mm | 59.4 mph | calculate → |
| 275/35R15 | 22.58" | -1.88% | +90 mm | 58.9 mph | calculate → |
| 205/55R15 | 23.88" | +3.76% | +20 mm | 62.3 mph | calculate → |
| 195/45R15 | 21.91" | -4.79% | +10 mm | 57.1 mph | calculate → |
| 175/60R15 | 23.27" | +1.11% | -10 mm | 60.7 mph | calculate → |
| 165/65R15 | 23.44" | +1.88% | -20 mm | 61.1 mph | calculate → |
| 22x8.00R15 | 22.00" | -4.40% | +18 mm | 57.4 mph | calculate → |
| 215/50R15 | 23.46" | +1.97% | +30 mm | 61.2 mph | calculate → |
| 175/50R15 | 21.89" | -4.88% | -10 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 | |
|---|---|---|---|---|---|
| 175/65R14 | 22.96" | -0.24% | -10 mm | 59.9 mph | compare → |
| 195/60R14 | 23.21" | +0.87% | +10 mm | 60.5 mph | compare → |
| 195/45R16 | 22.91" | -0.44% | +10 mm | 59.7 mph | calculate → |
| 205/55R14 | 22.88" | -0.58% | +20 mm | 59.7 mph | calculate → |
| 225/50R14 | 22.86" | -0.67% | +40 mm | 59.6 mph | calculate → |
| 175/50R16 | 22.89" | -0.53% | -10 mm | 59.7 mph | calculate → |
Try another size against 185/55R15
Questions
What size is 185/55R15 in inches?
185/55R15 is about 23.0" tall and 7.3" wide on a 15-inch rim — roughly a 23x7.50R15 in inch sizing.
What does 185/55R15 mean?
185 mm section width, sidewall 55% of the width (4.01"), radial construction, 15-inch rim.
What tire sizes are equivalent to 185/55R15?
On the same 15" rim, within 3% of the diameter: 225/45R15 (-0.17%), 205/50R15 (+0.26%), 295/35R15 (+0.51%), 165/60R15 (-0.94%), 175/60R15 (+1.11%), 245/40R15 (-1.28%).
How many revolutions per mile does a 185/55R15 tire make?
About 876 revolutions per mile (circumference 72.3").
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.