Geometry & DensityHigh-Precision Engineering Formula
in to mm Converter (Inches to Millimeters)
Convert beam depths, plate thicknesses, rebar diameters, and bolt clearances from inches to millimeters.
Interactive Conversion EngineSwap: mm → in
Inches
in
Result (mm)Millimeters
Standard Engineering Presets
in to mm Conversion Formula
To convert any value in Inches (in) to Millimeters (mm), multiply the quantity by the exact factor 25.4.
in to mm Conversion Chart
| in (Inches) | mm (Millimeters) | Conversion Ratio |
|---|---|---|
| 0.125 in | 3.175 mm | 1 in = 25.40000 mm |
| 0.25 in | 6.35 mm | 1 in = 25.40000 mm |
| 0.375 in | 9.525 mm | 1 in = 25.40000 mm |
| 0.5 in | 12.7 mm | 1 in = 25.40000 mm |
| 0.625 in | 15.875 mm | 1 in = 25.40000 mm |
| 0.75 in | 19.05 mm | 1 in = 25.40000 mm |
| 0.875 in | 22.225 mm | 1 in = 25.40000 mm |
| 1 in | 25.4 mm | 1 in = 25.40000 mm |
| 1.25 in | 31.75 mm | 1 in = 25.40000 mm |
| 1.5 in | 38.1 mm | 1 in = 25.40000 mm |
| 2 in | 50.8 mm | 1 in = 25.40000 mm |
| 3 in | 76.2 mm | 1 in = 25.40000 mm |
| 4 in | 101.6 mm | 1 in = 25.40000 mm |
| 6 in | 152.4 mm | 1 in = 25.40000 mm |
| 8 in | 203.2 mm | 1 in = 25.40000 mm |
| 10 in | 254 mm | 1 in = 25.40000 mm |
| 12 in | 304.8 mm | 1 in = 25.40000 mm |
| 14 in | 355.6 mm | 1 in = 25.40000 mm |
| 18 in | 457.2 mm | 1 in = 25.40000 mm |
| 24 in | 609.6 mm | 1 in = 25.40000 mm |
| 36 in | 914.4 mm | 1 in = 25.40000 mm |
Design Context
Structural Engineering Application
1 inch is defined as exactly 25.4 mm. Steel plate thicknesses, beam flange widths, and bolt hole clearances are converted with zero mathematical drift.
Engineering Pitfall
Common Conversion Mistake
Using 25 mm as an approximation; on a 36-inch beam depth, this creates a 14.4 mm (over 1/2 inch) error.
Direct Tool Integration
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Need to calculate section capacities, flexural reinforcement, or member buckling with these properties? AXIS runs instant ACI 318, AISC 360, and ASCE 7 checks with full step-by-step math derivations.