245/45R20 tire size

A 245/45R20 tire is 28.68 in (728.5 mm) tall and 9.65 in (245.0 mm) wide, and turns 703 revolutions per mile.

28.68 inOverall diameter
4.34 inSidewall height
703Revolutions per mile
28.7x9.6R20Flotation equivalent

245/45R20 dimensions
Measurement	Inches	Millimeters
Overall diameter	28.68 in	728.5 mm
Section width	9.65 in	245.0 mm
Sidewall height	4.34 in	110.3 mm
Rim diameter	20.00 in	508.0 mm
Circumference	90.10 in	2,289 mm
Revolutions per mile	703
Flotation equivalent	28.7x9.6R20 (approx.)

245/45R20 is a 20-inch tire with a 245 mm (9.65 in) section width and a 45% aspect ratio, giving a 4.34-inch sidewall and a flotation-style size of about 28.7x9.6R20.

Its overall diameter is 28.68 inches, so it rolls 90.1 inches per revolution and turns about 703 times per mile.

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

Compare 245/45R20 with plausible swaps

Sizes within 3% of 28.68 in diameter

315/35R20 28.68 in (0.00%)
325/30R21 28.68 in (−0.01%)
215/75R16 28.70 in (+0.05%)
275/40R20 28.66 in (−0.07%)
245/40R21 28.72 in (+0.12%)
245/50R19 28.65 in (−0.12%)
225/60R18 28.63 in (−0.18%)
285/30R22 28.73 in (+0.18%)
225/55R19 28.74 in (+0.22%)
275/45R19 28.74 in (+0.22%)
245/55R18 28.61 in (−0.25%)
245/35R22 28.75 in (+0.25%)
275/35R21 28.58 in (−0.36%)
245/60R17 28.57 in (−0.37%)
245/65R16 28.54 in (−0.49%)
225/65R17 28.52 in (−0.58%)
285/35R21 28.85 in (+0.60%)
275/30R22 28.50 in (−0.65%)
235/75R15 28.88 in (+0.69%)
265/50R18 28.43 in (−0.86%)
235/70R16 28.95 in (+0.95%)
225/70R16 28.40 in (−0.97%)
295/30R22 28.97 in (+1.00%)
265/45R19 28.39 in (−1.02%)
285/40R20 28.98 in (+1.03%)
265/40R20 28.35 in (−1.17%)
235/65R17 29.03 in (+1.21%)
255/35R22 29.03 in (+1.21%)
255/40R21 29.03 in (+1.22%)
235/45R20 28.33 in (−1.24%)
255/45R20 29.04 in (+1.24%)
255/50R19 29.04 in (+1.25%)
255/55R18 29.04 in (+1.26%)
255/60R17 29.05 in (+1.28%)
255/65R16 29.05 in (+1.29%)
255/70R15 29.06 in (+1.30%)
265/35R21 28.30 in (−1.32%)
295/40R19 28.29 in (−1.36%)
225/75R15 28.29 in (−1.37%)
285/45R19 29.10 in (+1.46%)
235/60R18 29.10 in (+1.47%)
265/30R22 28.26 in (−1.47%)
235/50R19 28.25 in (−1.50%)
295/35R21 29.13 in (+1.56%)
305/30R21 28.20 in (−1.66%)
235/55R19 29.18 in (+1.73%)
235/55R18 28.18 in (−1.76%)
295/35R20 28.13 in (−1.92%)
205/75R16 28.11 in (−2.00%)
235/60R17 28.10 in (−2.02%)
285/45R18 28.10 in (−2.03%)
225/75R16 29.29 in (+2.11%)
295/40R20 29.29 in (+2.13%)
265/35R22 29.30 in (+2.17%)
255/50R18 28.04 in (−2.24%)
235/45R21 29.33 in (+2.25%)
255/45R19 28.04 in (−2.25%)
255/40R20 28.03 in (−2.26%)
235/65R16 28.03 in (−2.28%)
255/35R21 28.03 in (−2.28%)
255/30R22 28.02 in (−2.29%)
265/40R21 29.35 in (+2.32%)
215/65R17 28.00 in (−2.36%)
285/40R19 27.98 in (−2.46%)
265/45R20 29.39 in (+2.47%)
295/30R21 27.97 in (−2.48%)
235/70R15 27.95 in (−2.54%)
275/25R24 29.41 in (+2.55%)
265/50R19 29.43 in (+2.62%)
315/30R22 29.44 in (+2.65%)
245/75R15 29.47 in (+2.75%)
245/70R16 29.50 in (+2.87%)
225/50R19 27.86 in (−2.87%)
285/35R20 27.85 in (−2.88%)
215/70R16 27.85 in (−2.90%)
265/60R17 29.52 in (+2.92%)
245/65R17 29.54 in (+2.99%)

Open 245/45R20 in the tire size calculator

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