Length Converter

Length converter: meters, feet, miles, kilometers, and more

Length converters translate distance measurements between metric and imperial systems—and between subdivisions within each. A blueprint in millimeters, a hiking trail in miles, and a product dimension in inches can all be compared once units align.

Enter a value, pick source and target units, and copy the result. Standard conversion factors apply; survey-grade work still needs official datums and certified equipment.

How to use this converter

1. Select the unit of your known measurement.
2. Type the length value.
3. Choose the output unit.
4. Copy into spreadsheets, CAD notes, or travel planning docs.

Before and after examples

Handy length anchors for quick checks.

Metric vs imperial length units

The metric system uses meters and prefixes: millimeters for precision machining, kilometers for road distance. US customary units favor inches, feet, yards, and statute miles. UK usage often mixes metric with miles on road signs.

One meter equals 3.28084 feet. One mile equals 1.60934 kilometers. Nautical miles differ from statute miles—marine charts use knots (nautical miles per hour); pick the mile type your source implies.

Where conversions go wrong

Confusing linear feet with square feet when estimating area—area needs the area converter, not length squared by hand. Mixing centimeters with millimeters without moving the decimal. Using rounded “three feet per meter” on a 50 m cable run adds noticeable error.

Fabric and lumber often list mixed units (2×4 lumber names vs actual dimensions). Convert the labeled measurement, not the trade name.

Construction, fitness, and e-commerce

DIY: Convert stud spacing or tile sizes when instructions switch between mm and inches. Running: compare 5K (~3.1 mi) with mile splits. Shipping: check whether a parcel’s longest side fits a carrier limit stated in cm.

E-commerce: marketplace listings in different regions may show product depth in inches while your warehouse uses centimeters—convert before slotting inventory.

Frequently asked questions