Length is the most-converted quantity there is: recipes for shelves, running distances, screen sizes and travel directions all switch between metric and US customary units. This converter uses the exact international definitions, so results are as precise as the numbers you put in.
How to use the length converter
- Type the distance in Value.
- Choose the unit you have in From and the unit you need in To.
- The converted value appears on the tape, and the table underneath lists the same distance in every supported unit.
Length conversion formula
Every unit is defined by how many meters it contains, so any conversion is a single multiplication:
For feet to meters the factor is 0.3048 ÷ 1 = 0.3048, so 6 ft × 0.3048 = 1.8288 m.
Common length conversions
| From | To | Multiply by |
|---|---|---|
| inches | centimeters | 2.54 (exact) |
| centimeters | inches | 0.393701 |
| feet | meters | 0.3048 (exact) |
| meters | feet | 3.28084 |
| yards | meters | 0.9144 (exact) |
| miles | kilometers | 1.609344 (exact) |
| kilometers | miles | 0.621371 |
| nautical miles | kilometers | 1.852 (exact) |
Metric and US customary at a glance
The metric system scales by powers of ten: 10 mm = 1 cm, 100 cm = 1 m, 1,000 m = 1 km. That makes metric conversions a matter of moving the decimal point.
The US customary system uses fixed but irregular steps: 12 inches = 1 foot, 3 feet = 1 yard, 1,760 yards = 1 mile. Since 1959 each of these has been defined in terms of the meter, which is why conversions between the two systems are exact.
Specialty length units
The converter also covers units you meet outside everyday measuring:
| Unit | Equals | Where it is used |
|---|---|---|
| mil (thou) | 0.001 in = 25.4 µm | Plastic film, wire coatings, sheet metal |
| hand | 4 in | Horse heights |
| fathom | 6 ft | Water depth on nautical charts |
| chain | 66 ft (22 yd) | Land surveying; a cricket pitch is one chain long |
| furlong | 660 ft (⅛ mi) | Horse racing |
| nautical mile | 1,852 m | Air and sea navigation |
| astronomical unit | 149,597,870,700 m | Distances within the solar system |
| light-year | ≈ 9.461 × 10¹⁵ m | Distances between stars |
Precision and rounding
Conversions between exactly defined units, such as inches and centimeters, introduce no error of their own — the result is only as precise as the measurement you started with. If you measured a board as 72 inches with a tape that reads to the nearest ⅛ inch, quoting the result as 182.88 cm suggests more certainty than you have; 182.9 cm is a more honest figure. As a rule of thumb, keep the same number of significant figures in the answer as in the original measurement.
Quick mental estimates
- A meter is a little more than a yard (about 39.4 inches).
- A kilometer is roughly 0.6 of a mile, so a 10 km race is about 6.2 miles.
- An inch is about 2.5 cm; a foot is about 30 cm.
- For heights in feet and inches, the height converter handles both parts at once.
Frequently asked questions
How many feet are in a meter?
One meter equals about 3.28084 feet. Going the other way, one foot is exactly 0.3048 meters.
Is an inch exactly 2.54 centimeters?
Yes. Since the international yard and pound agreement of 1959, the inch has been defined as exactly 2.54 cm, which makes the foot exactly 30.48 cm and the mile exactly 1,609.344 m.
What is a US survey foot?
An older definition (1200/3937 meters) used in some US land surveys. It differs from the international foot by about 2 parts per million. The US officially retired it at the end of 2022, but many legacy maps and deeds still use it.
What is the difference between a mile and a nautical mile?
A statute mile is 5,280 feet (1,609.344 m). A nautical mile is 1,852 m — about 1.15 statute miles — and is used in aviation and at sea because it corresponds to one minute of latitude.