275/40R18 tire size

A 275/40R18 tire is 26.7 inches (677 mm) tall and 10.8 inches (275 mm) wide, and fits a 18-inch wheel. In inch sizing it is about a 26.7x10.8R18.

Overall diameter26.66in677 mm

Drawn to scale from the nominal size.

Compare with another size Open in calculator Check wheel fitment

Shop 275/40R18 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
245/45R18	26.7″	+0.1%	9.6″	4.3″	18″
225/60R16	26.6″	−0.1%	8.9″	5.3″	16″
215/75R14	26.7″	+0.1%	8.5″	6.3″	14″
245/40R19	26.7″	+0.2%	9.6″	3.9″	19″
225/55R17	26.7″	+0.3%	8.9″	4.9″	17″
275/35R19	26.6″	−0.3%	10.8″	3.8″	19″
245/35R20	26.8″	+0.3%	9.6″	3.4″	20″
205/65R16	26.5″	−0.6%	8.1″	5.2″	16″
235/35R20	26.5″	−0.7%	9.3″	3.2″	20″
215/70R15	26.9″	+0.7%	8.5″	5.9″	15″
235/40R19	26.4″	−1.0%	9.3″	3.7″	19″
225/45R19	27.0″	+1.2%	8.9″	4.0″	19″

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

275: Section width: 275 mm (10.8 in) from sidewall to sidewall.
40: Aspect ratio: the sidewall is 40% as tall as the tire is wide, 110 mm (4.3 in).
R: Radial construction, used by almost every modern tire.
18: Fits a 18-inch wheel.

275/40R18 is about 26.7 inches tall and 10.8 inches wide, on a 18-inch wheel, roughly a 26.7x10.8R18 in inch sizing.

Nearly. It measures 26.7 inches, so it falls between 26 and 27 inches.

245/45R18, 225/60R16, 215/75R14 are the closest common sizes, all within 0.1% of its diameter, so the speedometer stays close to accurate.

245/50R18 is 3.7% taller, so at an indicated 60 mph you would really be doing 62.2 mph. Compare 275/40R18 and 245/50R18.

About 756 per mile (470 per km), from a 83.8-inch circumference.