275/40R20 tire size
A 275/40R20 tire stands 28.66 inches tall overall, on a 20-inch wheel, with a 110 mm sidewall and 275 mm of tread across. It turns roughly 704 times per mile.
- Overall diameter
- 28.66″
- 728.0 mm
- Sidewall height
- 110.0 mm
- 40% of 275 mm
- Circumference
- 90.0″
- 2,287 mm
- Revs per mile
- 704
- 437 per km
Reading the number
275 / 40 R 20 │ │ └─ rim diameter, 20 inches │ └──── aspect ratio, sidewall is 40% of width └──────── tread width, 275 mm sidewall = 275 × 0.40 = 110 mm diameter = (20 × 25.4) + (2 × 110) = 728 mm
Sizes that can replace 275/40R20
One rim step away, sorted by how close the rolling diameter stays.
Questions
›What does 275/40R20 mean?
275 is the tread width in millimetres. 40 is the aspect ratio, so the sidewall is 40% of 275 mm, or 110 mm. R means radial construction, and 20 is the wheel diameter in inches.
›How tall is a 275/40R20 tire?
28.66 inches, or 728 mm overall. That is the 20-inch rim plus a 110 mm sidewall at the top and another at the bottom.
›How many revolutions per mile does 275/40R20 do?
About 704 revolutions per mile, from a rolling circumference of 90 inches. Speedometers and odometers are calibrated against this figure, which is why changing size shifts both.
›What tires can replace 275/40R20?
Sizes within 3% of its rolling diameter and one rim step away, such as 255/45R20, 235/55R19, 245/45R19. Each is compared in full below.
Comparing against a size not listed? Open the calculator.