in³

cubic inch

VolumeSection modulusexact by definition

The cubic inch is the volume of a cube one inch on a side, exactly 1.6387064 × 10⁻⁵ m³ or about 16.39 mL. It survives in American engine displacement figures and in the definition of the US gallon, which is exactly 231 cubic inches. The factor is exact by definition.

1 in³ (Volume)0.016387064 L
1 in³ (Section modulus)16,387.064 mm³
As a unit of section modulus

The cubic inch is exactly 1.6387064 × 10⁻⁵ cubic metres, since the inch is exactly 0.0254 m. It is the section modulus unit of US steel design, where AISC tables list \(S_x\) and \(Z_x\) in cubic inches. A W12×26 beam has an elastic section modulus of about 33.4 in³.