How to use it
- Under Conversion Direction, choose mm → inch or inch → mm.
- Type the length in the Value field. Decimals are fine, for example 12.7.
- Read both results: Millimeters and Inches are shown together.
- Check the table below for common sizes, or use Share and Email to send the result to the workshop or site.
The formula
Inches = millimeters ÷ 25.4. Millimeters = inches × 25.4. The factor 25.4 is exact by definition, so the conversion has no rounding error beyond the digits you choose to keep.
Fractions and nominal sizes
The calculator gives decimal inches. To read it on a tape or drawing, round to the nearest fraction (1/16 in is 1.5875 mm). Nominal sizes are not exact: a 4 inch pipe is a nominal size, and its outside diameter is not 101.6 mm, so use the pipe standard’s table for real dimensions.
In UAE practice
Drawings in the UAE are in millimeters, but imported steel, hydraulic fittings, tyres, drill bits and equipment parts are often in inches. Rebar is ordered in mm (12, 16, 20, 25, 32), while US bar sizes are numbered in eighths of an inch. Always check the tolerance in the specification, because rounding a converted size can put a part out of tolerance.
Worked examples
- A 100 mm block or pipe is 3.937 in.
- A 16 mm rebar is 0.63 in.
- A 200 mm wall thickness is 7.874 in.
- A 6 inch hose or pipe fitting is 152.4 mm in metric terms.
Millimeters to inches table
Printable chart| Millimeters (mm) | Inches (in) |
|---|---|
| 1 | 0.039 in |
| 2 | 0.079 in |
| 3 | 0.118 in |
| 5 | 0.197 in |
| 6 | 0.236 in |
| 8 | 0.315 in |
| 10 | 0.394 in |
| 12 | 0.472 in |
| 16 | 0.63 in |
| 20 | 0.787 in |
| 25 | 0.984 in |
| 32 | 1.26 in |
| 40 | 1.575 in |
| 50 | 1.969 in |
| 75 | 2.953 in |
| 100 | 3.937 in |
| 150 | 5.906 in |
| 200 | 7.874 in |
Values use 1 inch = 25.4 mm.
Frequently asked questions
How many inches is 1 mm?
One millimeter is 1 ÷ 25.4 inch, about 0.0394 in.
How do I convert mm to inches?
Divide the millimeters by 25.4. Enter the value above or look it up in the table.
How do I convert inches to mm?
Multiply the inches by 25.4, or choose inch → mm in the calculator. For example, 1 inch is exactly 25.4 mm.
Is mm the standard in the UAE?
Yes. Drawings and specifications use millimeters, but imported equipment and fittings often list inches.
How do I turn the decimal inch into a fraction?
Multiply the decimal part by 16 (or 32 for finer work) and round to the nearest whole number to get sixteenths (or thirty-seconds) of an inch.
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<iframe src="https://www.equipmentsfinder.com/embed/field-tools/mm-to-inch" title="mm to inch converter" width="100%" height="620" style="border:0;max-width:720px" loading="lazy"></iframe> <p style="font-size:12px"><a href="https://www.equipmentsfinder.com/en-us/field-tools/mm-to-inch">mm to inch converter</a> by <a href="https://www.equipmentsfinder.com">EquipmentsFinder</a></p>