375/55R20 tire size
375/55R20 is a metric size: 36.2" tall, 14.8" wide, on a 20" rim — about a 36x15.00R20. The sidewall is 8.1" and the tire turns 557 times per mile.
375/55R20 specs
| Overall diameter (height) | 36.24" · 921 mm |
|---|---|
| Section width | 14.76" · 375 mm |
| Sidewall height | 8.12" · 206 mm (55% of width) |
| Rim diameter | 20" |
| Circumference | 113.85" · 2.892 m |
| Revolutions per mile | 557 (346 per km) |
| Inch (flotation) equivalent | 36x15.00R20 |
Equivalent sizes on a 20" 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 | |
|---|---|---|---|---|---|
| 35x12.50R20 common | 35.00" | -3.42% | -57 mm | 57.9 mph | calculate → |
| 37x12.50R20 | 37.00" | +2.10% | -57 mm | 61.3 mph | calculate → |
| 37x13.50R20 | 37.00" | +2.10% | -32 mm | 61.3 mph | calculate → |
| 295/65R20 | 35.10" | -3.15% | -80 mm | 58.1 mph | calculate → |
| 285/65R20 | 34.59" | -4.56% | -90 mm | 57.3 mph | calculate → |
| 325/60R20 | 35.35" | -2.44% | -50 mm | 58.5 mph | calculate → |
| 35x11.50R20 | 35.00" | -3.42% | -83 mm | 57.9 mph | calculate → |
| 35x13.50R20 | 35.00" | -3.42% | -32 mm | 57.9 mph | calculate → |
| 38x13.50R20 | 38.00" | +4.86% | -32 mm | 62.9 mph | calculate → |
| 38x15.50R20 | 38.00" | +4.86% | +19 mm | 62.9 mph | calculate → |
| 315/60R20 | 34.88" | -3.75% | -60 mm | 57.8 mph | calculate → |
| 37x11.50R20 | 37.00" | +2.10% | -83 mm | 61.3 mph | calculate → |
| 35x15.50R20 | 35.00" | -3.42% | +19 mm | 57.9 mph | calculate → |
| 36x13.50R20 | 36.00" | -0.66% | -32 mm | 59.6 mph | calculate → |
| 38x14.50R20 | 38.00" | +4.86% | -7 mm | 62.9 mph | calculate → |
| 36x15.50R20 | 36.00" | -0.66% | +19 mm | 59.6 mph | calculate → |
| 285/70R20 | 35.71" | -1.47% | -90 mm | 59.1 mph | calculate → |
| 37x14.50R20 | 37.00" | +2.10% | -7 mm | 61.3 mph | calculate → |
| 35x13.00R20 | 35.00" | -3.42% | -45 mm | 57.9 mph | calculate → |
| 35x14.50R20 | 35.00" | -3.42% | -7 mm | 57.9 mph | calculate → |
| 38x11.50R20 | 38.00" | +4.86% | -83 mm | 62.9 mph | calculate → |
| 345/60R20 | 36.30" | +0.16% | -30 mm | 60.1 mph | calculate → |
| 355/60R20 | 36.77" | +1.47% | -20 mm | 60.9 mph | calculate → |
Try another size against 375/55R20
Questions
What size is 375/55R20 in inches?
375/55R20 is about 36.2" tall and 14.8" wide on a 20-inch rim — roughly a 36x15.00R20 in inch sizing.
What does 375/55R20 mean?
375 mm section width, sidewall 55% of the width (8.12"), radial construction, 20-inch rim.
What tire sizes are equivalent to 375/55R20?
On the same 20" rim, within 3% of the diameter: 345/60R20 (+0.16%), 36x13.50R20 (-0.66%), 36x15.50R20 (-0.66%), 285/70R20 (-1.47%), 355/60R20 (+1.47%), 37x11.50R20 (+2.10%).
How many revolutions per mile does a 375/55R20 tire make?
About 557 revolutions per mile (circumference 113.9").
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.