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Tire size

245/40R20 tire size: dimensions explained

Factory size on the Lucid Air, Hyundai IONIQ 6. Below are the dimensions calculated from the size marking itself. Your vehicle's correct size, load index and speed rating are on the placard in the driver's door jamb; check it before buying.

MeasurementMetricImperial
Section width245 mm9.65 in
Sidewall height98 mm3.86 in
Overall diameter704 mm27.72 in
Wheel diameter508.0 mm20 in
Circumference2212 mm87.1 in
Revolutions per mile728

Calculated values: diameter = wheel + 2 × (width × aspect ratio). Real tires vary slightly by brand and model.

Reading the marking

245 is the section width in millimetres, 40 is the sidewall height as a percentage of that width, R means radial construction, and 20 is the wheel diameter in inches. A passenger (P or Euro-metric) tire and an LT tire in the same size are not interchangeable without checking load requirements.

Compare 245/40R20 with another size →

245/40R20 tires at Tire Rack

All-season

TireLoad/speedPrice per tire
Radar Dimax AS-8
Grand Touring All-Season		XL 99W$121.88View at Tire Rack
Pirelli P Zero All Season
Ultra High Performance All-Season		XL 99W$147.76View at Tire Rack

Highway / touring

TireLoad/speedPrice per tire
Pirelli Scorpion AS 4
Crossover/SUV Touring All-Season		XL 99V$292.00View at Tire Rack

Summer performance

TireLoad/speedPrice per tire
Nexen N FERA SU1
Ultra High Performance Summer		XL 99Y$118.20View at Tire Rack
Bridgestone Turanza 6
Grand Touring Summer		XL 99Y$186.98View at Tire Rack

Winter

TireLoad/speedPrice per tire
Pirelli Winter Sottozero 3
Performance Winter / Snow		XL 99W$233.85View at Tire Rack
Vredestein Wintrac Pro+
Performance Winter / Snow		XL 99Y$248.12View at Tire Rack

Showing the lowest-priced in-stock options in each category from 78 245/40R20 tires in Tire Rack's feed, sorted by price only. We don't rank by commission. Match or exceed the load index and speed rating on your placard.

Affiliate links: if you buy through a Tire Rack link, RightTread may earn a commission through CJ. It doesn't change your price. Prices are Tire Rack's per-tire prices from Tire Rack's product feed as of Nov 7, 2026, 10:23 PM PT. Prices change, so confirm on Tire Rack before you buy. Disclosure

Other sizes