Length & Distance Converter
Convert millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles with formulas and a full comparison table.
Converting length...
Enter a distance to convert
Results will show the selected conversion, formulas, a full unit table, and a visual comparison chart.
Conversion preview
What Is a Length and Distance Converter?
A length and distance converter changes one measurement unit into another without forcing you to remember every factor. This converter covers metric units such as millimeters, centimeters, meters, and kilometers; imperial units such as inches, feet, yards, and miles; and nautical miles for marine and aviation distances.
The calculator is useful for product dimensions, room plans, running distances, map measurements, hardware sizes, travel routes, and school problems. Enter one value, choose the starting and target units, and the result also includes a full comparison table so you can see nearby units at the same time.
How to Convert Length Units
The safest way to convert length units is to pass through meters. First multiply the input by the source unit's meter factor. Then divide that meter value by the target unit's meter factor. This single pivot keeps cm to inches, feet to meters, miles to km, and nautical miles to kilometers consistent.
converted value = input value x source meter factor / target meter factor
For example, five miles is first converted into meters: 5 x 1609.344 = 8046.72 meters. Kilometers use 1000 meters per unit, so 8046.72 / 1000 = 8.04672 kilometers.
How Length Conversion Works
Metric, Imperial, and Nautical Distance Units
Metric
mm, cm, m, km
Metric units scale by powers of ten, so they are usually easiest for science, engineering, maps, and international measurements.
Imperial
in, ft, yd, mi
Imperial units are common in the United States for height, construction, road distances, field dimensions, and product dimensions.
Nautical
nmi
A nautical mile is based on navigation and is used in marine and aviation contexts. One international nautical mile equals exactly 1852 meters.
Common Length Conversion Formulas
cm to inches
inches = centimeters / 2.54
inches to cm
centimeters = inches x 2.54
feet to meters
meters = feet x 0.3048
meters to feet
feet = meters / 0.3048
miles to km
kilometers = miles x 1.609344
km to miles
miles = kilometers / 1.609344
Length Conversion Reference Table
These exact factors are the foundation for the converter. Using exact international definitions prevents small errors from accumulating when switching between metric, imperial, and nautical units.
| Conversion | Exact value | Common use |
|---|---|---|
| 1 inch | 2.54 centimeters | screens, hardware, product dimensions |
| 1 foot | 0.3048 meters | height, rooms, construction |
| 1 yard | 0.9144 meters | sports fields, fabric, short distances |
| 1 mile | 1.609344 kilometers | roads, travel, running |
| 1 nautical mile | 1.852 kilometers | marine and aviation navigation |
| 1 kilometer | 1000 meters | maps, races, long distances |
Length and Distance Converter FAQ
How do I convert cm to inches?
Divide centimeters by 2.54 because one inch is exactly 2.54 centimeters. For example, 10 cm / 2.54 = 3.937007874 inches.
How do I convert inches to centimeters?
Multiply inches by 2.54 to get centimeters. The inch-to-centimeter definition is exact, so 1 inch always equals 2.54 cm.
How do I convert feet to meters?
Multiply feet by 0.3048. A six-foot measurement is 6 x 0.3048 = 1.8288 meters.
How do I convert miles to kilometers?
Multiply miles by 1.609344. A five-mile distance is 8.04672 kilometers because one international mile equals exactly 1609.344 meters.
What is the difference between a mile and a nautical mile?
A land mile is 1609.344 meters, while an international nautical mile is 1852 meters. Nautical miles are used for navigation, so one nautical mile is longer than one statute mile.
Why does the converter use meters as the base unit?
Meters are the SI base unit for length, and every supported unit has a clear factor to meters. Using one shared base keeps conversions consistent instead of chaining several rounded formulas together.
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