Length Converter
Convert between meters, feet, inches, kilometers, miles, yards, centimeters, millimeters and more. Real-time conversion, no signup, works entirely in your browser.
Convert Length
What does this Length Converter do?
This free online length converter converts between any two units of length instantly. Whether you're working on a DIY project, doing homework, planning a trip, or converting measurements for work, this tool gives you accurate results in real time.
It supports both the metric system (millimeters, centimeters, meters, kilometers, micrometers) and the imperial/US customary system (inches, feet, yards, miles), plus nautical miles for maritime and aviation use. All conversions use internationally recognized, exact conversion factors.
Everything runs locally in your browser. No server, no signup, no tracking. Your measurements never leave your device.
How to use the Length Converter
- Enter a value: Type the number you want to convert in the "From" field.
- Pick your source unit: Select the unit you're converting from (e.g., meters, feet, inches).
- Pick your target unit: Select the unit you want to convert to (e.g., feet, miles, centimeters).
- See the result instantly: The converted value appears in the "To" field and in the result box below — no button press needed.
- Use quick conversions: Click any of the preset buttons below to instantly convert common values like "1 m → ft" or "1 km → mi".
- Swap units: Click the swap button to reverse the conversion direction in one click.
- Copy the result: Use the "Copy Result" button to grab the converted value for use elsewhere.
Why use this Length Converter?
Real-time conversion
As you type, the result updates instantly. No button press needed, no waiting.
10 units supported
Millimeters, centimeters, meters, kilometers, micrometers, inches, feet, yards, miles, and nautical miles.
One-click swap
Swap the from and to units instantly with a single click. No need to re-enter the value.
Copy & reset
Copy the result to your clipboard or reset the converter to its default state with one click.
100% private
Everything runs in your browser. No server, no logs, no tracking. Your data never leaves your device.
Works offline
Once the page loads, the converter works without an internet connection. Perfect for travel or remote areas.
Length conversion factors
Here are the exact conversion factors used by this converter. All values are based on international standards.
| From | To | Multiply by | Example |
|---|---|---|---|
| Meters (m) | Feet (ft) | 3.28084 | 10 m = 32.8084 ft |
| Feet (ft) | Meters (m) | 0.3048 | 10 ft = 3.048 m |
| Inches (in) | Centimeters (cm) | 2.54 | 12 in = 30.48 cm |
| Centimeters (cm) | Inches (in) | 0.393701 | 30 cm = 11.811 in |
| Kilometers (km) | Miles (mi) | 0.621371 | 5 km = 3.10686 mi |
| Miles (mi) | Kilometers (km) | 1.609344 | 5 mi = 8.04672 km |
| Yards (yd) | Meters (m) | 0.9144 | 10 yd = 9.144 m |
| Nautical Miles (nmi) | Kilometers (km) | 1.852 | 10 nmi = 18.52 km |
| Millimeters (mm) | Inches (in) | 0.0393701 | 100 mm = 3.93701 in |
| Micrometers (µm) | Millimeters (mm) | 0.001 | 1000 µm = 1 mm |
Metric vs. imperial: what's the difference?
The world uses two main systems of measurement for length: the metric system and the imperial (or US customary) system. Understanding the difference helps you choose the right unit for the job.
The metric system
Used by almost every country in the world (the US is a notable exception). The metric system is based on powers of 10, which makes conversions between units simple — just move the decimal point. The base unit is the meter.
- Millimeter (mm): 1/1000 of a meter. Used for small precision measurements.
- Centimeter (cm): 1/100 of a meter. Common for everyday measurements.
- Meter (m): The base unit. Used for room dimensions, heights, and distances.
- Kilometer (km): 1000 meters. Used for longer distances like road trips.
- Micrometer (µm): 1/1,000,000 of a meter. Used in science and engineering.
The imperial / US customary system
Used primarily in the United States, and informally in the UK and a few other countries. The relationships between units are less uniform, so conversions require specific factors.
- Inch (in): 1/12 of a foot. Used for small measurements.
- Foot (ft): 12 inches. Common for heights and room dimensions.
- Yard (yd): 3 feet. Used for fabric, sports fields, and some construction.
- Mile (mi): 5,280 feet. Used for road distances.
Nautical miles
A nautical mile is based on the Earth's circumference — specifically, one minute of latitude. It equals exactly 1.852 kilometers. Nautical miles are used in aviation and maritime navigation because they align with the Earth's coordinate system.
Common length conversion use cases
DIY and home improvement
- Converting room dimensions from feet to meters for flooring or paint
- Checking if furniture will fit in a space
- Converting fabric measurements for sewing and upholstery
Travel and navigation
- Understanding speed limits and distance signs in foreign countries
- Converting hiking trail lengths between kilometers and miles
- Reading nautical charts with nautical miles
School and academics
- Physics and engineering homework with unit conversions
- Geography exercises comparing distances
- Science labs measuring small lengths in millimeters or micrometers
Fitness and sports
- Converting race distances (5K, 10K, marathon) between km and miles
- Tracking running or cycling distances in different units
- Converting pool lengths for swimming workouts