255/50R21 tire size

A 255/50R21 tire is 31.04 in (788.4 mm) tall and 10.04 in (255.0 mm) wide, and turns 650 revolutions per mile.

• 31.04 inOverall diameter
• 5.02 inSidewall height
• 650Revolutions per mile
• 31.0x10.0R21Flotation equivalent

255/50R21 is a 21-inch tire with a 255 mm (10.04 in) section width and a 50% aspect ratio, giving a 5.02-inch sidewall and a flotation-style size of about 31.0x10.0R21.

Its overall diameter is 31.04 inches, so it rolls 97.5 inches per revolution and turns about 650 times per mile.

54 other sizes in this list are within 3% of that diameter.

Compare 255/50R21 with plausible swaps

• 275/55R19 vs 255/50R21 (−0.42%)
• 235/65R19 vs 255/50R21 (−0.04%)
• 255/60R19 vs 255/50R21 (+0.03%)
• 305/45R20 vs 255/50R21 (−0.75%)
• 275/50R20 vs 255/50R21 (−0.68%)
• 255/55R20 vs 255/50R21 (+0.01%)
• 285/50R20 vs 255/50R21 (+0.58%)
• 255/45R21 vs 255/50R21 (−3.23%)
• 275/45R21 vs 255/50R21 (−0.95%)
• 255/50R21 vs 285/45R21 (+0.19%)
• 255/50R21 vs 265/50R21 (+1.27%)
• 255/50R21 vs 275/50R21 (+2.54%)
• 255/50R21 vs 275/40R22 (−1.22%)
• 255/50R21 vs 285/40R22 (−0.20%)
• 255/50R21 vs 295/40R22 (+0.81%)
• 255/50R21 vs 265/45R22 (+1.13%)

Sizes within 3% of 31.04 in diameter

• 255/55R20 31.04 in (+0.01%)
• 255/60R19 31.05 in (+0.03%)
• 255/65R18 31.05 in (+0.04%)
• 235/65R19 31.03 in (−0.04%)
• 255/70R17 31.06 in (+0.05%)
• 275/65R17 31.07 in (+0.11%)
• 31x10.50R15 31.00 in (−0.13%)
• 31x10.50R16 31.00 in (−0.13%)
• 275/60R18 30.99 in (−0.15%)
• 285/45R21 31.10 in (+0.19%)
• 285/40R22 30.98 in (−0.20%)
• 275/55R19 30.91 in (−0.42%)
• 235/75R17 30.88 in (−0.52%)
• 305/30R24 31.20 in (+0.53%)
• 285/50R20 31.22 in (+0.58%)
• 275/50R20 30.83 in (−0.68%)
• 305/45R20 30.81 in (−0.75%)
• 295/40R22 31.29 in (+0.81%)
• 275/45R21 30.74 in (−0.95%)
• 285/30R24 30.73 in (−0.99%)
• 265/45R22 31.39 in (+1.13%)
• 275/40R22 30.66 in (−1.22%)
• 265/75R15 30.65 in (−1.26%)
• 265/50R21 31.43 in (+1.27%)
• 285/60R18 31.46 in (+1.37%)
• 245/75R17 31.47 in (+1.38%)
• 245/55R20 30.61 in (−1.38%)
• 265/70R16 30.61 in (−1.40%)
• 265/55R20 31.48 in (+1.41%)
• 265/65R17 30.56 in (−1.53%)
• 245/65R18 30.54 in (−1.61%)
• 265/60R18 30.52 in (−1.67%)
• 265/65R18 31.56 in (+1.69%)
• 245/70R17 30.50 in (−1.73%)
• 285/65R17 31.59 in (+1.76%)
• 265/55R19 30.48 in (−1.81%)
• 265/70R17 31.61 in (+1.83%)
• 305/40R22 31.61 in (+1.83%)
• 245/75R16 30.47 in (−1.84%)
• 295/45R20 30.45 in (−1.89%)
• 265/50R20 30.43 in (−1.95%)
• 265/75R16 31.65 in (+1.97%)
• 305/35R22 30.41 in (−2.04%)
• 215/85R16 30.39 in (−2.09%)
• 265/45R21 30.39 in (−2.09%)
• 235/85R16 31.73 in (+2.22%)
• 265/40R22 30.35 in (−2.23%)
• 275/45R22 31.74 in (+2.27%)
• 295/40R21 30.29 in (−2.41%)
• 225/75R17 30.29 in (−2.42%)
• 235/80R17 31.80 in (+2.46%)
• 275/50R21 31.83 in (+2.54%)
• 235/55R20 30.18 in (−2.78%)
• 275/55R20 31.91 in (+2.80%)

Open 255/50R21 in the tire size calculator

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.