Instantly convert millimeters to inches (and back) including ± tolerances. Quick-reference table for common engineering dimensions. Free, no sign-up.
In aerospace and mechanical engineering, technical drawings may combine millimeter dimensions (ISO/European standards) with inch dimensions (American MIL, AS, ANSI standards). This converter switches instantly between units, propagating ± tolerances to preserve the required precision. It is especially useful when preparing an AS9102 FAI package from a US drawing expressed in inches.
The built-in reference table displays equivalences for common dimensions (0.1 mm to 500 mm) without manual calculation. Converted values include min and max limits, ready for direct use in EN9102 Form 3. No sign-up required — enter your dimension and tolerance, the result appears in real time in both directions.
| mm | in |
|---|---|
| 0.1 | 0.003937 |
| 0.5 | 0.019685 |
| 1 | 0.03937 |
| 2 | 0.07874 |
| 3 | 0.11811 |
| 5 | 0.19685 |
| 6 | 0.23622 |
| 8 | 0.314961 |
| 10 | 0.393701 |
| 12 | 0.472441 |
| 15 | 0.590551 |
| 20 | 0.787402 |
| 25 | 0.984252 |
| 25.4(exact) | 1 |
| 30 | 1.181102 |
| 50 | 1.968504 |
| 75 | 2.952756 |
| 100 | 3.937008 |
| 150 | 5.905512 |
| 200 | 7.874016 |
| 254(exact) | 10 |
| 300 | 11.811024 |
| 500 | 19.685039 |
1 inch = 25.4 mm exactly (ISO 31-1)
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