Length Converter

Last updated: October 23, 2026. All unit factors are exact international definitions.

How to Use the Length Converter

1. Enter the value you want to convert.
2. Choose the "From" unit (for example inches) and the "To" unit (for example centimeters). Use the swap button to reverse them, or tap a popular conversion.
3. Read the result. The big result, the formula and the "All Units" grid update as you type. Copy the result with one click.
4. Pick the precision. Leave decimals on Auto, or choose 2 to 10 decimal places.

For heights and furniture sizes, use the feet-and-inches boxes under the converter. When you convert to inches, the tool also shows the nearest 1/16 inch, which is useful for woodworking and DIY.

Exact Length Conversion Factors

Since the international yard and pound agreement of 1959, imperial length units are defined exactly in terms of the metric system. That means these relationships are not approximations:

Length Conversion Chart

Each row shows what 1 of that unit equals in other units.

Inches to Centimeters

Multiply inches by 2.54. For example, 10 inches × 2.54 = 25.4 cm. To go the other way, divide centimeters by 2.54.

Feet to Meters

Multiply feet by 0.3048. For example, 10 feet × 0.3048 = 3.048 m. To convert meters to feet, divide by 0.3048 (or multiply by about 3.28084).

Miles to Kilometers

Multiply miles by 1.609344. For example, 5 miles × 1.609344 = 8.04672 km. To convert kilometers to miles, divide by 1.609344 (or multiply by about 0.621371). A marathon is 42.195 km, or about 26.22 miles.

Height Chart: Feet and Inches to Centimeters

To convert a height, change it to total inches (feet × 12 + inches) and multiply by 2.54. For example, 5 ft 7 in = 67 in × 2.54 = 170.18 cm. Related: the BMI calculator and the ideal weight calculator both use height.

Where Length Conversion Matters

• Home and DIY. Furniture, curtains, flooring and appliances are often listed in a different unit than your tape measure. Convert the listing to your unit before you buy.
• Shipping and e-commerce. Carriers set size limits and charge by dimensions, so cm and inch values must be converted correctly. For area, use the area converter.
• Construction and engineering. Drawings may mix meters, millimeters and feet. Keep one unit per calculation and convert at the end.
• Travel and sport. Road signs in miles, running events in kilometers, and aviation or sailing in nautical miles (1 nmi = 1.852 km).
• School and science. Use the same unit throughout a problem. For the other common conversions, try the weight, temperature and volume converters.

Common Conversion Mistakes

• Mixing up yards and meters. A yard (0.9144 m) is slightly shorter than a meter. They are not interchangeable.
• Forgetting that 1 foot is 12 inches. Convert feet and inches to one unit before multiplying.
• Rounding too early. Keep extra decimals during a calculation and round only the final answer.
• Confusing statute and nautical miles. A nautical mile (1.852 km) is longer than a statute mile (1.609 km).
• Survey feet. The old U.S. survey foot differs from the international foot by about 2 parts per million. It was retired at the end of 2022, and this converter uses the international foot.

Metric and Imperial Systems in Brief

The meter is the base unit of length in the metric system (SI). Since 1983 it has been defined as the distance light travels in a vacuum in 1/299,792,458 of a second. Most countries use metric units in daily life. The United States still uses U.S. customary units such as inches, feet and miles, and the UK uses a mix, with distances on road signs in miles. On July 1, 1959, several countries agreed that the international yard equals exactly 0.9144 meters, which fixed every other imperial length exactly as well.