255/40R19 tire size
A 255/40R19 tire stands 27.03 inches tall overall, on a 19-inch wheel, with a 102 mm sidewall and 255 mm of tread across. It turns roughly 746 times per mile.
- Overall diameter
- 27.03″
- 686.6 mm
- Sidewall height
- 102.0 mm
- 40% of 255 mm
- Circumference
- 84.9″
- 2,157 mm
- Revs per mile
- 746
- 464 per km
Reading the number
255 / 40 R 19 │ │ └─ rim diameter, 19 inches │ └──── aspect ratio, sidewall is 40% of width └──────── tread width, 255 mm sidewall = 255 × 0.40 = 102 mm diameter = (19 × 25.4) + (2 × 102) = 686.6 mm
Sizes that can replace 255/40R19
One rim step away, sorted by how close the rolling diameter stays.
Questions
›What does 255/40R19 mean?
255 is the tread width in millimetres. 40 is the aspect ratio, so the sidewall is 40% of 255 mm, or 102 mm. R means radial construction, and 19 is the wheel diameter in inches.
›How tall is a 255/40R19 tire?
27.03 inches, or 686.6 mm overall. That is the 19-inch rim plus a 102 mm sidewall at the top and another at the bottom.
›How many revolutions per mile does 255/40R19 do?
About 746 revolutions per mile, from a rolling circumference of 84.9 inches. Speedometers and odometers are calibrated against this figure, which is why changing size shifts both.
›What tires can replace 255/40R19?
Sizes within 3% of its rolling diameter and one rim step away, such as 245/45R18, 245/45R19, 235/45R18. Each is compared in full below.
Comparing against a size not listed? Open the calculator.