37x13.50R20 tire size
37x13.50R20 is a flotation (inch) size: 37.0" tall, 13.5" wide, on a 20" rim — about a 340/65R20. The sidewall is 8.5" and the tire turns 545 times per mile.
37x13.50R20 specs
| Overall diameter (height) | 37.00" · 940 mm |
|---|---|
| Section width | 13.50" · 343 mm |
| Sidewall height | 8.50" · 216 mm (63% of width) |
| Rim diameter | 20" |
| Circumference | 116.24" · 2.952 m |
| Revolutions per mile | 545 (339 per km) |
| Closest metric size | 340/65R20 |
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 | |
|---|---|---|---|---|---|
| 37x12.50R20 | 37.00" | 0.00% | -25 mm | 60.0 mph | compare → |
| 325/60R20 | 35.35" | -4.45% | -18 mm | 57.3 mph | compare → |
| 38x13.50R20 | 38.00" | +2.70% | 0 mm | 61.6 mph | compare → |
| 38x15.50R20 | 38.00" | +2.70% | +51 mm | 61.6 mph | compare → |
| 37x11.50R20 | 37.00" | 0.00% | -51 mm | 60.0 mph | calculate → |
| 36x13.50R20 | 36.00" | -2.70% | 0 mm | 58.4 mph | calculate → |
| 38x14.50R20 | 38.00" | +2.70% | +25 mm | 61.6 mph | calculate → |
| 37x14.50R20 | 37.00" | 0.00% | +25 mm | 60.0 mph | calculate → |
| 375/55R20 | 36.24" | -2.05% | +32 mm | 58.8 mph | calculate → |
| 36x15.50R20 | 36.00" | -2.70% | +51 mm | 58.4 mph | calculate → |
| 38x11.50R20 | 38.00" | +2.70% | -51 mm | 61.6 mph | calculate → |
| 285/70R20 | 35.71" | -3.49% | -58 mm | 57.9 mph | calculate → |
| 38.5x13.50R20 | 38.50" | +4.05% | 0 mm | 62.4 mph | calculate → |
| 38.5x14.50R20 | 38.50" | +4.05% | +25 mm | 62.4 mph | calculate → |
| 395/60R20 | 38.66" | +4.49% | +52 mm | 62.7 mph | calculate → |
| 355/60R20 | 36.77" | -0.62% | +12 mm | 59.6 mph | calculate → |
| 345/60R20 | 36.30" | -1.89% | +2 mm | 58.9 mph | calculate → |
Try another size against 37x13.50R20
Questions
What size is 37x13.50R20 in inches?
37x13.50R20 is about 37.0" tall and 13.5" wide on a 20-inch rim — roughly a 340/65R20 in inch sizing.
What does 37x13.50R20 mean?
37" overall diameter, 13.50" section width, radial, 20" rim.
What tire sizes are equivalent to 37x13.50R20?
On the same 20" rim, within 3% of the diameter: 37x11.50R20 (0.00%), 37x12.50R20 (0.00%), 37x14.50R20 (0.00%), 355/60R20 (-0.62%), 345/60R20 (-1.89%), 375/55R20 (-2.05%).
How many revolutions per mile does a 37x13.50R20 tire make?
About 545 revolutions per mile (circumference 116.2").
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.