42x13.50R20 tire size
42x13.50R20 is a flotation (inch) size: 42.0" tall, 13.5" wide, on a 20" rim — about a 340/80R20. The sidewall is 11.0" and the tire turns 480 times per mile.
42x13.50R20 specs
| Overall diameter (height) | 42.00" · 1067 mm |
|---|---|
| Section width | 13.50" · 343 mm |
| Sidewall height | 11.00" · 279 mm (81% of width) |
| Rim diameter | 20" |
| Circumference | 131.95" · 3.351 m |
| Revolutions per mile | 480 (298 per km) |
| Closest metric size | 340/80R20 |
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 | |
|---|---|---|---|---|---|
| 40x15.50R20 | 40.00" | -4.76% | +51 mm | 57.1 mph | calculate → |
| 40x14.50R20 | 40.00" | -4.76% | +25 mm | 57.1 mph | calculate → |
| 42x14.50R20 | 42.00" | 0.00% | +25 mm | 60.0 mph | calculate → |
| 40x13.50R20 | 40.00" | -4.76% | 0 mm | 57.1 mph | calculate → |
| 42x15.00R20 | 42.00" | 0.00% | +38 mm | 60.0 mph | calculate → |
| 42.5x13.50R20 | 42.50" | +1.19% | 0 mm | 60.7 mph | calculate → |
| 41x14.50R20 | 41.00" | -2.38% | +25 mm | 58.6 mph | calculate → |
| 43x14.50R20 | 43.00" | +2.38% | +25 mm | 61.4 mph | calculate → |
| 43x15.00R20 | 43.00" | +2.38% | +38 mm | 61.4 mph | calculate → |
| 44x13.50R20 | 44.00" | +4.76% | 0 mm | 62.9 mph | calculate → |
| 44x19.50R20 | 44.00" | +4.76% | +152 mm | 62.9 mph | calculate → |
| 44x21.00R20 | 44.00" | +4.76% | +190 mm | 62.9 mph | calculate → |
Try another size against 42x13.50R20
Questions
What size is 42x13.50R20 in inches?
42x13.50R20 is about 42.0" tall and 13.5" wide on a 20-inch rim — roughly a 340/80R20 in inch sizing.
What does 42x13.50R20 mean?
42" overall diameter, 13.50" section width, radial, 20" rim.
What tire sizes are equivalent to 42x13.50R20?
On the same 20" rim, within 3% of the diameter: 42x14.50R20 (0.00%), 42x15.00R20 (0.00%), 42.5x13.50R20 (+1.19%), 41x14.50R20 (-2.38%), 43x14.50R20 (+2.38%), 43x15.00R20 (+2.38%).
How many revolutions per mile does a 42x13.50R20 tire make?
About 480 revolutions per mile (circumference 131.9").
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.