Conversion factor
1 in = 25.4 mm
Converted through the base unit (m): 0.0254 m per in ÷ 0.001 m per mm.
SI · NIST SP 811
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Converted value
1 in = 25.4 mm
1 × 25.4 = 25.4 mm.
SI · NIST SP 811
How this was calculated
- Convert 1 in to the base unit (m): 1 × 0.0254 = 0.0254 m.
- Convert 0.0254 m to mm: ÷ 0.001 = 25.4 mm.
Engineering disclaimer: Conversion factors are exact SI constants (NIST SP 811; 1959 international yard & pound agreement). Verify manufacturer-specified units and conversion conventions for your application.