45x14.50R20 tire size
45x14.50R20 is a flotation (inch) size: 45.0" tall, 14.5" wide, on a 20" rim — about a 370/85R20. The sidewall is 12.5" and the tire turns 448 times per mile.
45x14.50R20 specs
| Overall diameter (height) | 45.00" · 1143 mm |
|---|---|
| Section width | 14.50" · 368 mm |
| Sidewall height | 12.50" · 318 mm (86% of width) |
| Rim diameter | 20" |
| Circumference | 141.37" · 3.591 m |
| Revolutions per mile | 448 (278 per km) |
| Closest metric size | 370/85R20 |
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 | |
|---|---|---|---|---|---|
| 44x13.50R20 | 44.00" | -2.22% | -25 mm | 58.7 mph | calculate → |
| 44x19.50R20 | 44.00" | -2.22% | +127 mm | 58.7 mph | calculate → |
| 46x19.50R20 | 46.00" | +2.22% | +127 mm | 61.3 mph | calculate → |
| 43x14.50R20 | 43.00" | -4.44% | 0 mm | 57.3 mph | calculate → |
| 43x15.00R20 | 43.00" | -4.44% | +13 mm | 57.3 mph | calculate → |
| 44x21.00R20 | 44.00" | -2.22% | +165 mm | 58.7 mph | calculate → |
Try another size against 45x14.50R20
Questions
What size is 45x14.50R20 in inches?
45x14.50R20 is about 45.0" tall and 14.5" wide on a 20-inch rim — roughly a 370/85R20 in inch sizing.
What does 45x14.50R20 mean?
45" overall diameter, 14.50" section width, radial, 20" rim.
What tire sizes are equivalent to 45x14.50R20?
On the same 20" rim, within 3% of the diameter: 44x13.50R20 (-2.22%), 44x19.50R20 (-2.22%), 44x21.00R20 (-2.22%), 46x19.50R20 (+2.22%), 43x14.50R20 (-4.44%), 43x15.00R20 (-4.44%).
How many revolutions per mile does a 45x14.50R20 tire make?
About 448 revolutions per mile (circumference 141.4").
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.