Length Converter

Convert between meters, centimeters, inches, feet, miles, and more. Accurately convert length and distance units for everyday use and professional work.

How to Use

  1. Enter the length value

    Type the length value you want to convert.

  2. Select the units

    Choose the source unit (e.g., inches) and the target unit (e.g., centimeters).

  3. View the result

    Click Convert to see the converted length value.

What is length unit conversion?

Length unit conversion means expressing the same distance using different units of measurement. The world is largely split into two systems: the metric system (SI), where mm, cm, m, and km are linked by powers of ten around the meter, and the imperial system, where inches, feet, yards, and miles relate through factors of 12, 3, and 1760.

This converter handles eight units in both directions: mm, cm, m, km, inches, feet, yards, and miles. Each value is first converted to the base unit (the meter) and then to the target unit, so even cross-system conversions like inches to km are handled accurately in a single step.

Common uses

  • Check inch/ft dimensions of imported furniture or clothing in cm
  • Reconcile mixed mm and m values in drawings and design specs
  • Compare running or hiking distances in miles and km

Calculation formula

Every unit is converted through a factor that expresses it in the base unit (meters).

result = value × fromFactor / toFactor

Here, fromFactor is how many meters one source unit equals, and toFactor is how many meters one target unit equals. For example, an inch is 0.0254 and a centimeter is 0.01.

Example) converting 10 inches to cm:
10 × 0.0254 / 0.01 = 25.4 cm

Results are rounded and shown to six decimal places.

Frequently Asked Questions

How many centimeters are in one inch?
One inch is exactly 2.54 centimeters (cm). This value was fixed by the 1959 international yard and pound agreement, and conversely one centimeter is about 0.3937 inches.
How many meters are in one foot?
One foot is exactly 0.3048 meters (m). One foot equals 12 inches, and one meter is about 3.2808 feet.
How many kilometers are in one mile?
One mile is exactly 1.609344 kilometers (km). One mile equals 1760 yards and is mainly used for road distances in the United States and the United Kingdom.
How does a nautical mile differ from a mile?
One mile is about 1.609 km, while one nautical mile is exactly 1.852 km. A nautical mile is defined as the distance of one minute of latitude and is used in navigation and aviation, whereas the mile in this converter is the ordinary land mile.
How many meters are in one yard?
One yard is exactly 0.9144 meters (m). One yard equals 3 feet (36 inches) and is often used as a distance unit in golf and American football.
What is the difference between the metric and imperial systems?
The metric system is a decimal system in which mm, cm, m, and km are linked by powers of ten around the meter, making calculations simple. The imperial system, by contrast, uses irregular multiples such as inch (12) → foot (3) → yard (1760) → mile, so a tool like this converter is handy when moving between the two.
Can I convert mm to km in one step?
Yes. Because every unit is converted through meters, even conversions with large scale differences like mm to km are accurate. For example, 1,000,000 mm equals 1 km.
How are decimals handled in the result?
Results are rounded and shown to six decimal places. So converting one inch to mm gives a clean 25.4 mm, but converting one meter to inches shows an approximate six-digit value like 39.370079 inches.
2026 international standards

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