Length Unit Conversion Tool
Whether you're an engineer, student, designer, traveler, or DIY enthusiast, you often need to convert between metric and imperial length units in daily life or professional work. To help you perform these conversions quickly and accurately, we proudly present our Universal Length Unit Converter—supporting instant, bidirectional conversion among the following 9 commonly used units:
- Millimeters (mm)
- Centimeters (cm)
- Meters (m)
- Kilometers (km)
- Inches (in)
- Yards (yd)
- U.S. survey feet (ft-us)
- International feet (ft)
- Miles (mi)
Just enter a value, select the source and target units, and get results instantly! Say goodbye to manual calculations, lookup tables, and unit confusion.
🔁 Core Length Conversion Formulas
Metric Units (based on the meter)
| Conversion | Formula |
|---|---|
| mm → cm | cm = mm ÷ 10 |
| cm → m | m = cm ÷ 100 |
| m → km | km = m ÷ 1,000 |
| mm → m | m = mm ÷ 1,000 |
| cm → km | km = cm ÷ 100,000 |
Imperial Units
| Conversion | Formula |
|---|---|
| in → ft | ft = in ÷ 12 |
| ft → yd | yd = ft ÷ 3 |
| yd → mi | mi = yd ÷ 1,760 |
| in → yd | yd = in ÷ 36 |
💡 Note:
- International foot (ft) is the global standard: 1 ft = 0.3048 m
- U.S. survey foot (ft-us) is used in U.S. geodetic surveys: 1 ft-us ≈ 0.3048006096 m
(The difference is negligible for most applications but matters in high-precision surveying.)
Metric ↔ Imperial Key Reference Values
| Base Relationship | Exact Value |
|---|---|
| 1 inch (in) | = 25.4 millimeters (mm) |
| 1 meter (m) | = 39.3701 inches (in) |
| 1 foot (ft) | = 0.3048 meters (m) |
| 1 yard (yd) | = 0.9144 meters (m) |
| 1 mile (mi) | = 1.609344 kilometers (km) |
📏 Common Length Unit Conversion Reference Table
| mm | cm | m | km | in | ft | yd | mi |
|---|---|---|---|---|---|---|---|
| 1 | 0.1 | 0.001 | 0.000001 | 0.03937 | 0.00328 | 0.00109 | 6.21e-7 |
| 10 | 1 | 0.01 | 0.00001 | 0.3937 | 0.0328 | 0.0109 | 6.21e-6 |
| 100 | 10 | 0.1 | 0.0001 | 3.937 | 0.328 | 0.109 | 6.21e-5 |
| 1,000 | 100 | 1 | 0.001 | 39.37 | 3.281 | 1.094 | 0.000621 |
| 10,000 | 1,000 | 10 | 0.01 | 393.7 | 32.81 | 10.94 | 0.00621 |
| 100,000 | 10,000 | 100 | 0.1 | 3,937 | 328.1 | 109.4 | 0.0621 |
| 1,000,000 | 100,000 | 1,000 | 1 | 39,370 | 3,281 | 1,094 | 0.621 |
| — | — | — | 1.609 | 63,360 | 5,280 | 1,760 | 1 |
✅ Note: The last row shows equivalent values for 1 mile (mi).
✨ Tool Highlights
- Full coverage of 9 units: Seamlessly switch between metric and imperial systems—from millimeters to miles
- High-precision calculation: Uses internationally standardized conversion factors with support for multiple decimal places
- Smart unit recognition: Automatically distinguishes between international foot (ft) and U.S. survey foot (ft-us) for professional surveying needs
- Completely free & ad-free: No login required—focused purely on utility
- Responsive interface: Works smoothly on mobile phones, tablets, and desktop computers
🌐 Try It Now!
📏 Make length conversion effortless!
Whether you're doing homework, drafting technical drawings, renovating your home, planning a trip, or working on engineering designs—this tool is your reliable companion.
🚀 Experience fast, accurate, and free length unit conversion today!