315/35R21 tire size

A 315/35R21 tire is 29.68 in (753.9 mm) tall and 12.40 in (315.0 mm) wide, and turns 679 revolutions per mile.

• 29.68 inOverall diameter
• 4.34 inSidewall height
• 679Revolutions per mile
• 29.7x12.4R21Flotation equivalent

315/35R21 is a 21-inch tire with a 315 mm (12.40 in) section width and a 35% aspect ratio, giving a 4.34-inch sidewall and a flotation-style size of about 29.7x12.4R21.

Its overall diameter is 29.68 inches, so it rolls 93.2 inches per revolution and turns about 679 times per mile.

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

Compare 315/35R21 with plausible swaps

• 265/50R19 vs 315/35R21 (−0.84%)
• 245/55R19 vs 315/35R21 (−0.24%)
• 275/50R19 vs 315/35R21 (+0.49%)
• 265/45R20 vs 315/35R21 (−0.98%)
• 305/40R20 vs 315/35R21 (−0.25%)
• 245/50R20 vs 315/35R21 (−0.12%)
• 275/45R20 vs 315/35R21 (+0.21%)
• 295/35R21 vs 315/35R21 (−1.86%)
• 265/40R21 vs 315/35R21 (−1.13%)
• 275/40R21 vs 315/35R21 (−0.07%)
• 245/45R21 vs 315/35R21 (0.00%)
• 315/35R21 vs 285/40R21 (+0.99%)
• 315/35R21 vs 255/45R21 (+1.19%)
• 315/35R21 vs 315/30R22 (−0.81%)
• 315/35R21 vs 285/35R22 (+0.58%)
• 315/35R21 vs 255/40R22 (+1.18%)

Sizes within 3% of 29.68 in diameter

• 245/45R21 29.68 in (0.00%)
• 275/40R21 29.66 in (−0.07%)
• 245/50R20 29.65 in (−0.12%)
• 275/45R20 29.74 in (+0.21%)
• 245/55R19 29.61 in (−0.24%)
• 265/70R15 29.61 in (−0.25%)
• 305/40R20 29.61 in (−0.25%)
• 245/60R18 29.57 in (−0.36%)
• 245/65R17 29.54 in (−0.48%)
• 275/50R19 29.83 in (+0.49%)
• 265/60R17 29.52 in (−0.54%)
• 285/35R22 29.85 in (+0.58%)
• 245/70R16 29.50 in (−0.60%)
• 235/75R16 29.88 in (+0.66%)
• 245/75R15 29.47 in (−0.72%)
• 275/55R18 29.91 in (+0.77%)
• 315/30R22 29.44 in (−0.81%)
• 265/50R19 29.43 in (−0.84%)
• 275/25R24 29.41 in (−0.90%)
• 235/70R17 29.95 in (+0.92%)
• 265/45R20 29.39 in (−0.98%)
• 285/40R21 29.98 in (+0.99%)
• 275/60R17 29.99 in (+1.05%)
• 30x9.50R15 30.00 in (+1.07%)
• 265/40R21 29.35 in (−1.13%)
• 235/65R18 30.03 in (+1.17%)
• 255/40R22 30.03 in (+1.18%)
• 235/45R21 29.33 in (−1.19%)
• 255/45R21 30.04 in (+1.19%)
• 255/50R20 30.04 in (+1.21%)
• 255/55R19 30.04 in (+1.22%)
• 255/60R18 30.05 in (+1.23%)
• 255/65R17 30.05 in (+1.25%)
• 255/70R16 30.06 in (+1.26%)
• 265/35R22 29.30 in (−1.27%)
• 295/40R20 29.29 in (−1.31%)
• 225/75R16 29.29 in (−1.33%)
• 285/45R20 30.10 in (+1.41%)
• 235/60R19 30.10 in (+1.42%)
• 235/55R20 30.18 in (+1.67%)
• 235/55R19 29.18 in (−1.70%)
• 295/35R21 29.13 in (−1.86%)
• 235/60R18 29.10 in (−1.95%)
• 285/45R19 29.10 in (−1.96%)
• 225/75R17 30.29 in (+2.04%)
• 295/40R21 30.29 in (+2.06%)
• 255/70R15 29.06 in (−2.11%)
• 255/65R16 29.05 in (−2.12%)
• 255/60R17 29.05 in (−2.14%)
• 255/55R18 29.04 in (−2.15%)
• 255/50R19 29.04 in (−2.16%)
• 255/45R20 29.04 in (−2.18%)
• 255/40R21 29.03 in (−2.19%)
• 235/65R17 29.03 in (−2.20%)
• 255/35R22 29.03 in (−2.20%)
• 265/40R22 30.35 in (+2.24%)
• 285/40R20 28.98 in (−2.37%)
• 215/85R16 30.39 in (+2.39%)
• 265/45R21 30.39 in (+2.39%)
• 295/30R22 28.97 in (−2.40%)
• 305/35R22 30.41 in (+2.44%)
• 235/70R16 28.95 in (−2.45%)
• 265/50R20 30.43 in (+2.53%)
• 295/45R20 30.45 in (+2.60%)
• 245/75R16 30.47 in (+2.65%)
• 265/55R19 30.48 in (+2.68%)
• 235/75R15 28.88 in (−2.71%)
• 245/70R17 30.50 in (+2.77%)
• 285/35R21 28.85 in (−2.79%)
• 265/60R18 30.52 in (+2.83%)
• 245/65R18 30.54 in (+2.89%)
• 265/65R17 30.56 in (+2.97%)

Open 315/35R21 in the tire size calculator

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