255/40R20 tire size

A 255/40R20 tire is 28.0 inches (712 mm) tall and 10.0 inches (255 mm) wide, and fits a 20-inch wheel. In inch sizing it is about a 28.0x10.0R20.

Overall diameter28.03in712 mm

Drawn to scale from the nominal size.

Compare with another size Open in calculator Check wheel fitment

Shop 255/40R20 tires

Opens the store’s own search

Prices and stock change often, so check a few stores. We don’t earn anything from these links.

Size	Diameter	Difference	Width	Sidewall	Wheel
255/45R19	28.0″	+0.0%	10.0″	4.5″	19″
235/65R16	28.0″	−0.0%	9.3″	6.0″	16″
255/30R22	28.0″	−0.0%	10.0″	3.0″	22″
215/65R17	28.0″	−0.1%	8.5″	5.5″	17″
235/60R17	28.1″	+0.3%	9.3″	5.6″	17″
235/55R18	28.2″	+0.5%	9.3″	5.1″	18″
215/70R16	27.9″	−0.6%	8.5″	5.9″	16″
235/50R19	28.3″	+0.8%	9.3″	4.6″	19″
225/75R15	28.3″	+0.9%	8.9″	6.6″	15″
245/35R21	27.8″	−1.0%	9.6″	3.4″	21″
225/55R18	27.7″	−1.0%	8.9″	4.9″	18″
235/45R20	28.3″	+1.1%	9.3″	4.2″	20″

Within 3% of the original diameter is the range most tire shops treat as a direct swap. Check load index and clearance too.

255: Section width: 255 mm (10.0 in) from sidewall to sidewall.
40: Aspect ratio: the sidewall is 40% as tall as the tire is wide, 102 mm (4.0 in).
R: Radial construction, used by almost every modern tire.
20: Fits a 20-inch wheel.

255/40R20 is about 28.0 inches tall and 10.0 inches wide, on a 20-inch wheel, roughly a 28.0x10.0R20 in inch sizing.

Yes. At 28.0 inches it is sold and fitted as a 28-inch tire.

255/45R19, 235/65R16, 255/30R22 are the closest common sizes, all within 0.0% of its diameter, so the speedometer stays close to accurate.

255/45R20 is 3.6% taller, so at an indicated 60 mph you would really be doing 62.1 mph. Compare 255/40R20 and 255/45R20.

About 719 per mile (447 per km), from a 88.1-inch circumference.