Precision Length Converter (2026)
Effortlessly convert any value between millimeters, inches, centimeters, meters, feet, or microns—with visual comparison, memory history, scale bar, and quick presets. Full formulae and best practices included.
Calculator
👩🔬 Input & Settings
🔍 Result & Formula
0.3937 in
10 mm = 0.3937 in
📏 Visual Comparison
10 mm
=
0.3937 in
* Visual bars are to scale
🚀 Quick Conversions
🕓 History
What is the Precision Length Converter?
A versatile calculator to instantly convert any length – millimeters, inches, centimeters, feet, meters, microns – with real-time accuracy and learning tools for engineering, DIY, education, and everyday use.
How it Works (With Formulae)
To convert from Unit A to Unit B:
\[ \text{Value}_B = \frac{\text{Value}_A \times \text{rate}_A}{\text{rate}_B} \] Example for mm → in: \[ \text{inches} = \frac{\text{mm}}{25.4} \]
\[ \text{Value}_B = \frac{\text{Value}_A \times \text{rate}_A}{\text{rate}_B} \] Example for mm → in: \[ \text{inches} = \frac{\text{mm}}{25.4} \]
Conversion Table (mm → inch, rounded to 1/64”)
| Millimeters (mm) | Inches (decimal) | Inches (fraction) |
|---|---|---|
| 1 mm | 0.0394 | 3/64 " |
| 2 mm | 0.0787 | 5/64 " |
| 5 mm | 0.1969 | 13/64 " |
| 10 mm | 0.3937 | 25/64 " |
| 25.4 mm | 1.0000 | 1 " |
| 50 mm | 1.9685 | 1 31/32 " |
| 100 mm | 3.9370 | 3 15/16 " |
Full chart: Inches to mm Converter
How to Use
- Enter your value, choose source and target units
- Click convert (or use quick preset or swap)
- View result, formula, scale bar, and copy to clipboard
- Review recent conversion history + reference info below
Common Uses
- Engineering technical diagrams using imperial and metric
- DIY projects and international product measurements
- Jewelry/watchmaking for micro measurements
- Bolt, screw, fitting sizes
FAQ
Are results accurate?
Yes, all conversions use exact mathematical formulas. Decimal rounding is for user-friendliness.
Can I copy my result?
Yes—click “Copy Result” for quick use in other apps.
What’s the fastest way to convert 1 inch?
Use the “1 in → mm” quick preset or enter 1 and swap units.
Where can I find more details on inches vs mm?
See our complete guide here.
Does the tool keep my conversions?
Yes, the last 5 conversions appear in history. Click any to repeat.
