How to Convert 9mm to Inches
9 mm ÷ 25.4 = 0.3543 inches. To find the nearest 32nd, multiply by 32: 0.3543 × 32 = 11.34, which rounds to 11/32.
On a Tape Measure
Standard US tape measures show marks at every 1/16 inch. The nearest mark to 9mm is the 3/8″ mark. For rough layout work, use the 3/8″ mark.