205/40R18 tire size

A 205/40R18 tire is 24.46 in (621.2 mm) tall and 8.07 in (205.0 mm) wide, and turns 825 revolutions per mile.

205/40R18 dimensions
MeasurementInchesMillimeters
Overall diameter24.46 in621.2 mm
Section width8.07 in205.0 mm
Sidewall height3.23 in82.0 mm
Rim diameter18.00 in457.2 mm
Circumference76.83 in1,952 mm
Revolutions per mile825
Flotation equivalent24.5x8.1R18 (approx.)

205/40R18 is a 18-inch tire with a 205 mm (8.07 in) section width and a 40% aspect ratio, giving a 3.23-inch sidewall and a flotation-style size of about 24.5x8.1R18.

Its overall diameter is 24.46 inches, so it rolls 76.8 inches per revolution and turns about 825 times per mile.

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

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Sizes within 3% of 24.46 in diameter

Open 205/40R18 in the tire size calculator

Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.