Millimeters to Inches Converter
Convert millimeters to inches instantly. Perfect for engineering, jewelry, screen sizes, and precision measurements. Includes chart and formula.
Formula
inches = mm ÷ 25.4
25.4 mm ÷ 25.4 = 1.0000 inches
About Millimeters to Inches Conversion
The millimeter (mm) is a metric unit equal to one thousandth of a meter, used worldwide for precision measurements in engineering, manufacturing, and science. The inch is an imperial unit divided into fractions (1/16, 1/8, 1/4) or decimals, used in the US and UK for construction, hardware, and screen sizes. One inch equals exactly 25.4 millimeters.
This conversion is critical in engineering and manufacturing (metric bolts vs. imperial sockets), jewelry sizing (ring sizes are often in mm), screen and display specifications (phone screens listed in mm diagonally), 3D printing (designs may use either system), and woodworking (drill bits and saw blades come in both metric and imperial). Knowing that 25.4 mm = 1 inch is the key reference point.
MM to Inches Conversion Table
| Millimeters | Inches | Common Use |
|---|---|---|
| 1 mm | 0.039 in | Credit card thickness |
| 3 mm | 0.118 in | Small screw |
| 5 mm | 0.197 in | Pencil diameter |
| 6 mm | 0.236 in | ~1/4 inch |
| 8 mm | 0.315 in | ~5/16 inch |
| 10 mm | 0.394 in | ~3/8 inch |
| 12 mm | 0.472 in | ~1/2 inch |
| 15 mm | 0.591 in | ~9/16 inch |
| 19 mm | 0.748 in | ~3/4 inch |
| 25 mm | 0.984 in | ~1 inch |
| 25.4 mm | 1.000 in | Exactly 1 inch |
| 50 mm | 1.969 in | ~2 inches |