How to Convert 4mm to Inches
4 mm ÷ 25.4 = 0.1575 inches. To find the nearest 32nd, multiply by 32: 0.1575 × 32 = 5.04, which rounds to 5/32.
On a Tape Measure
Standard US tape measures show marks at every 1/16 inch. The nearest mark to 4mm is the 3/16″ mark. For rough layout work, use the 1/8″ mark.