275/30R21 tire size

A 275/30R21 tire is 27.50 in (698.4 mm) tall and 10.83 in (275.0 mm) wide, and turns 733 revolutions per mile.

• 27.50 inOverall diameter
• 3.25 inSidewall height
• 733Revolutions per mile
• 27.5x10.8R21Flotation equivalent

275/30R21 is a 21-inch tire with a 275 mm (10.83 in) section width and a 30% aspect ratio, giving a 3.25-inch sidewall and a flotation-style size of about 27.5x10.8R21.

Its overall diameter is 27.50 inches, so it rolls 86.4 inches per revolution and turns about 733 times per mile.

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

Compare 275/30R21 with plausible swaps

• 295/35R19 vs 275/30R21 (−1.33%)
• 235/45R19 vs 275/30R21 (−0.62%)
• 265/40R19 vs 275/30R21 (−0.54%)
• 305/35R19 vs 275/30R21 (−0.33%)
• 275/40R19 vs 275/30R21 (+0.60%)
• 245/45R19 vs 275/30R21 (+0.67%)
• 225/50R19 vs 275/30R21 (+1.32%)
• 265/35R20 vs 275/30R21 (−0.70%)
• 275/35R20 vs 275/30R21 (+0.30%)
• 245/40R20 vs 275/30R21 (+0.80%)
• 285/35R20 vs 275/30R21 (+1.30%)
• 275/30R21 vs 245/35R21 (+0.93%)
• 275/30R21 vs 295/30R21 (+1.72%)
• 275/30R21 vs 275/35R21 (+3.94%)
• 275/30R21 vs 245/30R22 (+1.06%)
• 275/30R21 vs 295/25R22 (+1.13%)

Sizes within 3% of 27.50 in diameter

• 225/65R16 27.52 in (+0.07%)
• 245/60R16 27.57 in (+0.29%)
• 275/35R20 27.58 in (+0.30%)
• 305/35R19 27.41 in (−0.33%)
• 225/70R15 27.40 in (−0.34%)
• 265/45R18 27.39 in (−0.39%)
• 245/55R17 27.61 in (+0.42%)
• 225/60R17 27.63 in (+0.49%)
• 245/50R18 27.65 in (+0.54%)
• 265/40R19 27.35 in (−0.54%)
• 275/40R19 27.66 in (+0.60%)
• 235/45R19 27.33 in (−0.62%)
• 215/55R18 27.31 in (−0.67%)
• 245/45R19 27.68 in (+0.67%)
• 265/35R20 27.30 in (−0.70%)
• 215/75R15 27.70 in (+0.73%)
• 295/40R18 27.29 in (−0.74%)
• 225/75R14 27.29 in (−0.76%)
• 245/40R20 27.72 in (+0.80%)
• 235/50R18 27.25 in (−0.89%)
• 225/55R18 27.74 in (+0.90%)
• 275/45R18 27.74 in (+0.90%)
• 245/35R21 27.75 in (+0.93%)
• 245/30R22 27.79 in (+1.06%)
• 295/25R22 27.81 in (+1.13%)
• 235/55R17 27.18 in (−1.16%)
• 215/60R17 27.16 in (−1.23%)
• 215/70R16 27.85 in (+1.29%)
• 285/35R20 27.85 in (+1.30%)
• 225/50R19 27.86 in (+1.32%)
• 295/35R19 27.13 in (−1.33%)
• 205/75R15 27.11 in (−1.42%)
• 235/60R16 27.10 in (−1.43%)
• 225/40R20 27.09 in (−1.49%)
• 235/70R15 27.95 in (+1.66%)
• 255/50R17 27.04 in (−1.66%)
• 255/45R18 27.04 in (−1.68%)
• 255/40R19 27.03 in (−1.69%)
• 255/35R20 27.03 in (−1.70%)
• 295/30R21 27.97 in (+1.72%)
• 285/40R19 27.98 in (+1.75%)
• 215/65R16 27.00 in (−1.79%)
• 27x8.50R14 27.00 in (−1.80%)
• 215/65R17 28.00 in (+1.85%)
• 285/40R18 26.98 in (−1.89%)
• 225/45R19 26.97 in (−1.90%)
• 295/30R20 26.97 in (−1.92%)
• 255/30R22 28.02 in (+1.92%)
• 235/65R16 28.03 in (+1.93%)
• 255/35R21 28.03 in (+1.93%)
• 255/40R20 28.03 in (+1.95%)
• 255/45R19 28.04 in (+1.96%)
• 255/50R18 28.04 in (+1.98%)
• 285/45R18 28.10 in (+2.19%)
• 235/60R17 28.10 in (+2.21%)
• 205/75R16 28.11 in (+2.22%)
• 295/35R20 28.13 in (+2.31%)
• 225/50R18 26.86 in (−2.32%)
• 285/35R19 26.85 in (−2.33%)
• 215/70R15 26.85 in (−2.35%)
• 235/55R18 28.18 in (+2.48%)
• 305/30R21 28.20 in (+2.58%)
• 245/35R20 26.75 in (−2.71%)
• 225/55R17 26.74 in (−2.73%)
• 235/50R19 28.25 in (+2.75%)
• 285/30R20 26.73 in (−2.78%)
• 265/30R22 28.26 in (+2.78%)
• 245/40R19 26.72 in (−2.84%)
• 225/75R15 28.29 in (+2.88%)
• 295/40R19 28.29 in (+2.89%)
• 215/75R14 26.70 in (−2.91%)
• 265/35R21 28.30 in (+2.94%)
• 245/45R18 26.68 in (−2.96%)

Open 275/30R21 in the tire size calculator

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