Length Converter
Convert any length between metric and imperial units, from millimeters to miles, and see every unit side by side.
All units
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Length is the measurement we convert most often. You might need a screen size in centimeters, a running distance in miles, or a room’s dimensions for furniture ordered from abroad. This converter handles metric and imperial units in both directions and shows the result in every unit at once, so you rarely need to convert twice.
How to use the length converter
- Type a number in the Value box.
- Choose the unit you have in From and the unit you want in To.
- Read the result instantly. The table below it shows the same length in every other unit.
Use Swap units to reverse the conversion in one click.
Exact conversion factors
Every imperial length unit is defined in terms of the meter, so these factors are exact:
| Unit | In meters | Handy equivalent |
|---|---|---|
| 1 inch | 0.0254 m | 2.54 cm |
| 1 foot | 0.3048 m | 12 inches |
| 1 yard | 0.9144 m | 3 feet |
| 1 mile | 1,609.344 m | 5,280 feet |
| 1 nautical mile | 1,852 m | ≈ 1.1508 miles |
Quick mental math shortcuts
You won’t always have a converter to hand. These approximations come in handy:
- Kilometers to miles: multiply by 0.6, or multiply by 5 and divide by 8. So 10 km is about 6.2 miles.
- Miles to kilometers: multiply by 1.6. A marathon of 26.2 miles is about 42.2 km.
- Meters to feet: multiply by 3, then add 10%. So 2 m is about 6.6 ft.
- Inches to centimeters: multiply by 2.5 for a close estimate. A 6-inch phone is about 15 cm.
Metric vs. imperial in everyday life
Most of the world uses the metric system. The United States mostly uses imperial units, and the United Kingdom uses a mix: miles on road signs, but centimeters at school and in shops. That mix is why conversions come up so often when you shop internationally, follow a recipe or DIY plan from another country, or travel. Metric units scale by tens (10 mm = 1 cm, 100 cm = 1 m, 1,000 m = 1 km), which makes them easier to work with. Imperial units need memorized multipliers such as 12, 3 and 1,760.
Frequently asked questions
How many centimeters are in an inch?
Exactly 2.54. The inch was defined as 25.4 millimeters by international agreement in 1959, so the conversion is exact, not rounded.
How do I convert feet and inches to centimeters?
Convert the whole height to inches first (feet × 12 + inches), then multiply by 2.54. For example, 5 ft 9 in is 69 inches, and 69 × 2.54 = 175.26 cm.
What is the difference between a mile and a nautical mile?
A standard (statute) mile is 1,609.344 meters. A nautical mile is 1,852 meters and is based on one minute of latitude, which is why ships and aircraft use it for navigation.