Popular length conversions
- Millimeters to centimeters1 mm = 0.1 cm
- Millimeters to meters1 mm = 0.001 m
- Millimeters to kilometers1 mm = 0.000001 km
- Millimeters to inches1 mm = 0.0393701 in
- Millimeters to feet1 mm = 0.00328084 ft
- Millimeters to yards1 mm = 0.00109361 yd
- Millimeters to miles1 mm = 6.21371×10⁻⁷ mi
- Centimeters to millimeters1 cm = 10 mm
- Centimeters to meters1 cm = 0.01 m
- Centimeters to kilometers1 cm = 0.00001 km
- Centimeters to inches1 cm = 0.393701 in
- Centimeters to feet1 cm = 0.0328084 ft
- Centimeters to yards1 cm = 0.0109361 yd
- Centimeters to miles1 cm = 0.00000621371 mi
- Meters to millimeters1 m = 1,000 mm
- Meters to centimeters1 m = 100 cm
- Meters to kilometers1 m = 0.001 km
- Meters to inches1 m = 39.3701 in
- Meters to feet1 m = 3.28084 ft
- Meters to yards1 m = 1.09361 yd
- Meters to miles1 m = 0.000621371 mi
- Kilometers to millimeters1 km = 1,000,000 mm
- Kilometers to centimeters1 km = 100,000 cm
- Kilometers to meters1 km = 1,000 m
- Kilometers to inches1 km = 39,370.1 in
- Kilometers to feet1 km = 3,280.84 ft
- Kilometers to yards1 km = 1,093.61 yd
- Kilometers to miles1 km = 0.621371 mi
- Inches to millimeters1 in = 25.4 mm
- Inches to centimeters1 in = 2.54 cm
- Inches to meters1 in = 0.0254 m
- Inches to kilometers1 in = 0.0000254 km
- Inches to feet1 in = 0.0833333 ft
- Inches to yards1 in = 0.0277778 yd
- Inches to miles1 in = 0.0000157828 mi
- Feet to millimeters1 ft = 304.8 mm
- Feet to centimeters1 ft = 30.48 cm
- Feet to meters1 ft = 0.3048 m
- Feet to kilometers1 ft = 0.0003048 km
- Feet to inches1 ft = 12 in
- Feet to yards1 ft = 0.333333 yd
- Feet to miles1 ft = 0.000189394 mi
- Yards to millimeters1 yd = 914.4 mm
- Yards to centimeters1 yd = 91.44 cm
- Yards to meters1 yd = 0.9144 m
- Yards to kilometers1 yd = 0.0009144 km
- Yards to inches1 yd = 36 in
- Yards to feet1 yd = 3 ft
- Yards to miles1 yd = 0.000568182 mi
- Miles to millimeters1 mi = 1,609,340 mm
- Miles to centimeters1 mi = 160,934 cm
- Miles to meters1 mi = 1,609.34 m
- Miles to kilometers1 mi = 1.60934 km
- Miles to inches1 mi = 63,360 in
- Miles to feet1 mi = 5,280 ft
- Miles to yards1 mi = 1,760 yd
- Nautical miles to kilometers1 nmi = 1.852 km
- Kilometers to nautical miles1 km = 0.539957 nmi
- Nautical miles to miles1 nmi = 1.15078 mi
- Miles to nautical miles1 mi = 0.868976 nmi
- Micrometers to millimeters1 µm = 0.001 mm
- Millimeters to micrometers1 mm = 1,000 µm
- Nanometers to meters1 nm = 1×10⁻⁹ m
- Meters to nanometers1 m = 1,000,000,000 nm
- Light-years to kilometers1 ly = 9,460,730,000,000 km
- Kilometers to light-years1 km = 1.057×10⁻¹³ ly
- Astronomical units to kilometers1 au = 149,598,000 km
- Kilometers to astronomical units1 km = 6.68459×10⁻⁹ au
About length units
Length is one of the seven SI base quantities. Since 1983 the metre has been defined by the distance light travels in a vacuum in 1/299,792,458 of a second, and since the 1959 international yard and pound agreement every US and imperial length unit is defined exactly in metres — an inch is exactly 25.4 mm. That is why conversions such as inches to centimetres are exact rather than approximate.
Length unit reference
| Unit | Symbol | Value in m | System |
|---|---|---|---|
| Millimeter | mm | 0.001 m | SI |
| Centimeter | cm | 0.01 m | SI |
| Meter | m | 1 m | SI |
| Kilometer | km | 1,000 m | SI |
| Inch | in | 0.0254 m | US customary |
| Foot | ft | 0.3048 m | US customary |
| Yard | yd | 0.9144 m | US customary |
| Mile | mi | 1,609.344 m | US customary |
| Nautical mile | nmi | 1,852 m | Other |
| Micrometer | µm | 0.000001 m | SI |
| Nanometer | nm | 1×10⁻⁹ m | SI |
| Picometer | pm | 1×10⁻¹² m | SI |
| Decimeter | dm | 0.1 m | SI |
| Ångström | Å | 1×10⁻¹⁰ m | Other |
| Mil (thou) | mil | 0.0000254 m | US customary |
| Hand | hh | 0.1016 m | Imperial |
| Link (Gunter) | li | 0.201168 m | Imperial |
| Rod | rd | 5.0292 m | Imperial |
| Chain | ch | 20.1168 m | Imperial |
| Furlong | fur | 201.168 m | Imperial |
| League (land) | lea | 4,828.032 m | Other |
| Fathom | ftm | 1.8288 m | Imperial |
| US survey foot | ft (US) | 0.30480061 m | US customary |
| Astronomical unit | au | 149,597,870,000 m | Other |
| Light-year | ly | 9.4607305×10¹⁵ m | Other |
| Parsec | pc | 3.0856776×10¹⁶ m | Other |
Frequently asked questions
What is the SI unit of length?
This converter uses the meter (m) as its reference unit; every other unit is defined relative to it.
How many length units can I convert?
26 units are supported here, across SI, US customary, Other, Imperial systems. Every pair can be converted in both directions.
Does this length converter work offline?
Yes. Once the page has loaded, every calculation runs locally in your browser — nothing is sent to a server.