285/45R21 tire size

A 285/45R21 tire is 31.10 in (789.9 mm) tall and 11.22 in (285.0 mm) wide, and turns 649 revolutions per mile.

• 31.10 inOverall diameter
• 5.05 inSidewall height
• 649Revolutions per mile
• 31.1x11.2R21Flotation equivalent

285/45R21 is a 21-inch tire with a 285 mm (11.22 in) section width and a 45% aspect ratio, giving a 5.05-inch sidewall and a flotation-style size of about 31.1x11.2R21.

Its overall diameter is 31.10 inches, so it rolls 97.7 inches per revolution and turns about 649 times per mile.

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

Compare 285/45R21 with plausible swaps

• 275/55R19 vs 285/45R21 (−0.61%)
• 235/65R19 vs 285/45R21 (−0.23%)
• 255/60R19 vs 285/45R21 (−0.16%)
• 305/45R20 vs 285/45R21 (−0.94%)
• 275/50R20 vs 285/45R21 (−0.87%)
• 255/55R20 vs 285/45R21 (−0.18%)
• 285/50R20 vs 285/45R21 (+0.39%)
• 265/55R20 vs 285/45R21 (+1.22%)
• 285/40R21 vs 285/45R21 (−3.61%)
• 265/45R21 vs 285/45R21 (−2.28%)
• 275/45R21 vs 285/45R21 (−1.14%)
• 255/50R21 vs 285/45R21 (−0.19%)
• 285/45R21 vs 265/50R21 (+1.08%)
• 285/45R21 vs 275/50R21 (+2.34%)
• 285/45R21 vs 285/40R22 (−0.39%)
• 285/45R21 vs 295/40R22 (+0.62%)
• 285/45R21 vs 265/45R22 (+0.94%)
• 285/45R21 vs 305/40R22 (+1.63%)

Sizes within 3% of 31.10 in diameter

• 275/65R17 31.07 in (−0.08%)
• 255/70R17 31.06 in (−0.14%)
• 255/65R18 31.05 in (−0.15%)
• 255/60R19 31.05 in (−0.16%)
• 255/55R20 31.04 in (−0.18%)
• 255/50R21 31.04 in (−0.19%)
• 235/65R19 31.03 in (−0.23%)
• 31x10.50R15 31.00 in (−0.32%)
• 31x10.50R16 31.00 in (−0.32%)
• 275/60R18 30.99 in (−0.34%)
• 305/30R24 31.20 in (+0.34%)
• 285/50R20 31.22 in (+0.39%)
• 285/40R22 30.98 in (−0.39%)
• 275/55R19 30.91 in (−0.61%)
• 295/40R22 31.29 in (+0.62%)
• 235/75R17 30.88 in (−0.71%)
• 275/50R20 30.83 in (−0.87%)
• 305/45R20 30.81 in (−0.94%)
• 265/45R22 31.39 in (+0.94%)
• 265/50R21 31.43 in (+1.08%)
• 275/45R21 30.74 in (−1.14%)
• 285/60R18 31.46 in (+1.18%)
• 285/30R24 30.73 in (−1.18%)
• 245/75R17 31.47 in (+1.19%)
• 265/55R20 31.48 in (+1.22%)
• 275/40R22 30.66 in (−1.41%)
• 265/75R15 30.65 in (−1.44%)
• 265/65R18 31.56 in (+1.49%)
• 285/65R17 31.59 in (+1.57%)
• 245/55R20 30.61 in (−1.57%)
• 265/70R16 30.61 in (−1.58%)
• 265/70R17 31.61 in (+1.63%)
• 305/40R22 31.61 in (+1.63%)
• 265/65R17 30.56 in (−1.72%)
• 265/75R16 31.65 in (+1.77%)
• 245/65R18 30.54 in (−1.80%)
• 265/60R18 30.52 in (−1.86%)
• 245/70R17 30.50 in (−1.91%)
• 265/55R19 30.48 in (−2.00%)
• 245/75R16 30.47 in (−2.03%)
• 235/85R16 31.73 in (+2.03%)
• 295/45R20 30.45 in (−2.08%)
• 275/45R22 31.74 in (+2.08%)
• 265/50R20 30.43 in (−2.14%)
• 305/35R22 30.41 in (−2.23%)
• 235/80R17 31.80 in (+2.27%)
• 215/85R16 30.39 in (−2.28%)
• 265/45R21 30.39 in (−2.28%)
• 275/50R21 31.83 in (+2.34%)
• 265/40R22 30.35 in (−2.42%)
• 295/40R21 30.29 in (−2.60%)
• 225/75R17 30.29 in (−2.61%)
• 275/55R20 31.91 in (+2.61%)
• 32x11.50R15 32.00 in (+2.90%)
• 305/50R20 32.01 in (+2.92%)
• 235/55R20 30.18 in (−2.96%)

Open 285/45R21 in the tire size calculator

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