215/40R18 tire size

A 215/40R18 tire is 24.77 in (629.2 mm) tall and 8.46 in (215.0 mm) wide, and turns 814 revolutions per mile.

• 24.77 inOverall diameter
• 3.39 inSidewall height
• 814Revolutions per mile
• 24.8x8.5R18Flotation equivalent

215/40R18 is a 18-inch tire with a 215 mm (8.46 in) section width and a 40% aspect ratio, giving a 3.39-inch sidewall and a flotation-style size of about 24.8x8.5R18.

Its overall diameter is 24.77 inches, so it rolls 77.8 inches per revolution and turns about 814 times per mile.

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

Compare 215/40R18 with plausible swaps

• 185/60R16 vs 215/40R18 (−0.13%)
• 225/50R16 vs 215/40R18 (+0.35%)
• 205/55R16 vs 215/40R18 (+0.43%)
• 215/45R17 vs 215/40R18 (−0.62%)
• 245/40R17 vs 215/40R18 (−0.22%)
• 225/45R17 vs 215/40R18 (+0.81%)
• 255/40R17 vs 215/40R18 (+1.05%)
• 205/50R17 vs 215/40R18 (+1.21%)
• 215/35R18 vs 215/40R18 (−3.42%)
• 205/40R18 vs 215/40R18 (−1.27%)
• 235/35R18 vs 215/40R18 (−1.19%)
• 245/35R18 vs 215/40R18 (−0.08%)
• 215/40R18 vs 255/35R18 (+1.03%)
• 215/40R18 vs 225/40R18 (+1.27%)
• 215/40R18 vs 235/40R18 (+2.54%)
• 215/40R18 vs 215/45R18 (+3.42%)
• 215/40R18 vs 245/30R19 (+0.06%)
• 215/40R18 vs 255/30R19 (+1.02%)

Sizes within 3% of 24.77 in diameter

• 245/30R19 24.79 in (+0.06%)
• 245/35R18 24.75 in (−0.08%)
• 195/70R14 24.75 in (−0.10%)
• 185/60R16 24.74 in (−0.13%)
• 245/40R17 24.72 in (−0.22%)
• 225/50R16 24.86 in (+0.35%)
• 205/60R15 24.69 in (−0.35%)
• 205/55R16 24.88 in (+0.43%)
• 215/45R17 24.62 in (−0.62%)
• 225/45R17 24.97 in (+0.81%)
• 195/65R15 24.98 in (+0.84%)
• 255/30R19 25.02 in (+1.02%)
• 255/35R18 25.03 in (+1.03%)
• 255/40R17 25.03 in (+1.05%)
• 235/35R18 24.48 in (−1.19%)
• 205/50R17 25.07 in (+1.21%)
• 185/65R15 24.47 in (−1.22%)
• 205/40R18 24.46 in (−1.27%)
• 225/40R18 25.09 in (+1.27%)
• 195/55R16 24.44 in (−1.32%)
• 235/40R17 24.40 in (−1.49%)
• 215/60R15 25.16 in (+1.56%)
• 225/35R19 25.20 in (+1.73%)
• 195/60R16 25.21 in (+1.78%)
• 265/30R19 25.26 in (+1.97%)
• 205/45R17 24.26 in (−2.05%)
• 205/70R14 25.30 in (+2.13%)
• 265/35R18 25.30 in (+2.15%)
• 215/55R16 25.31 in (+2.18%)
• 225/30R20 25.31 in (+2.19%)
• 235/45R17 25.33 in (+2.24%)
• 195/60R15 24.21 in (−2.26%)
• 225/35R18 24.20 in (−2.30%)
• 265/40R17 25.35 in (+2.32%)
• 185/70R14 24.20 in (−2.32%)
• 235/40R18 25.40 in (+2.54%)
• 225/40R17 24.09 in (−2.77%)
• 215/50R17 25.46 in (+2.80%)
• 205/50R16 24.07 in (−2.83%)
• 235/35R19 25.48 in (+2.84%)
• 205/65R15 25.49 in (+2.91%)
• 275/30R19 25.50 in (+2.92%)

Open 215/40R18 in the tire size calculator

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