285/40R20 tire size
A 285/40R20 tire stands 29.0 inches tall and 11.2 inches wide, with a 4.5-inch sidewall on a 20-inch rim.
- Overall height
- 29.0 in736 mm
- Section width
- 11.2 in285 mm
- Sidewall height
- 4.5 in114 mm
- Rim diameter
- 20 in508 mm
- Circumference
- 91.0 in2312 mm
- Revolutions per mile
- 696432 per km
- Inch size
- 29.0x11.2R20
Compare it with any other size in the tire size calculator.
Sizes you can swap to
These 20-inch sizes are within two width steps and 3% of a 285/40R20's overall height, the usual limit before the speedometer, ABS and transmission notice. The closest is 275/40R20, 1.1% shorter (0.31 in). Wider sizes also need room in the wheel well and a rim width that suits them.
Plus and minus sizes
Changing rim size means changing the sidewall to keep the same overall height. On 18-inch or 19-inch or 21-inch or 22-inch rims, these are the closest matches to a 285/40R20.
Other 20-inch sizes near 285/40R20
285 mm wide, other sidewalls
- 285/35R2027.9″
- 285/45R2030.1″
- 285/50R2031.2″
- 285/55R2032.3″
- 285/60R2033.5″
- 285/65R2034.6″
- 285/70R2035.7″
- 285/75R2036.8″
40 series, other widths
See the other sizes for this rim on 20-inch tire sizes.
Shop 285/40R20 tires
These open each store's own list of 285/40R20 tires, where you can filter by type, load and speed rating.
285/40R20 questions
How tall is a 285/40R20 tire?
About 29.0 inches (736 mm) from the ground to the top of the tread, unloaded. On the vehicle, carrying weight, it sits a little lower.
What does 285/40R20 mean?
285 is the section width in millimetres (11.2 in). 40 means the sidewall is 40% of that width: 114 mm, or 4.5 in. R means radial construction, and 20 is the rim diameter in inches.
Can I use 275/40R20 instead of 285/40R20?
275/40R20 is 1.1% shorter (0.31 in) and 10 mm narrower, which is inside the usual 3% rule. With it fitted, the speedometer shows 60 mph when you are doing 59.3 mph.
What is 285/40R20 in inches?
In inch terms it is 29.0x11.2R20: 29.0 inches tall, 11.2 inches wide, for a 20-inch rim.
How many revolutions per mile does a 285/40R20 make?
About 696 turns per mile, worked out from its unloaded circumference of 91.0 inches. Makers list slightly higher numbers for their own tires, because a loaded tire rolls on a smaller radius.