How to convert from square inches (in2) to cubic millimeters (mm3)?
The area in square inches (in2) must be multiplied by the thickness in inches and multiply by 16387. The result is a volume of cubic millimeters (mm3).
1 mm3 ≈ 1 in2 * 1 in * 16387
1 mm3 = 1 in2 * 1 in * 25.4 * 25.4 * 25.4 = 1 in2 * 1 in * 16387.064
1 in = 25.4 mm