Length Converter
Length Converter — runs in your browser. Inputs are not stored.
Length unit conversion
Enter values, then press Calculate.
The base unit is the meter (m). 1 mile = 1609.344 m, 1 nmi = 1852 m.
How to use
- Enter a number in Value and pick the starting unit in Unit. The default is 1 meter.
- The unit list is meter, kilometer, centimeter, millimeter, micrometer, nanometer, mile, yard, foot, inch, and nautical mile.
- Click Convert, or change the value or unit and the other units update together.
- Very small or large values may appear in scientific notation.
- Reset returns to 1 meter. Conversion happens only in the browser.
Key concepts
The base for length conversion is the meter (m). The input is converted to meters, then divided by each unit factor. 1 international mile = 1609.344 m, 1 nautical mile = 1852 m, 1 yard = 0.9144 m, 1 foot = 0.3048 m, 1 inch = 0.0254 m. Micrometers and nanometers are for optical and semiconductor scales. The value field accepts decimals. The table redraws as soon as you change the unit, so you can forget to click Convert. The micrometer symbol is shown as µm.
Even if you only need cm↔inch, this table shows inches and centimeters together. For weight, power, or pressure, use the weight, power, or engineering unit converters. Factors are for reference and may differ from legal metrology by one digit. Feet and inches are for building dimensions; nautical miles are for charts and aviation logs. Seeing every unit on one screen is handy when a spec mixes units. Temperature and weight are not in this table.
Example
Enter 1 mile and you get about 1.609 km, 1609.344 m, 1760 yards, and 5280 feet. 1852 m as nautical miles is 1 nmi. 10 cm is 100 mm, about 3.937 in. A nanometer value makes meters tiny in scientific notation. Choose 5 km and you get 5000 m, about 3.107 mile, about 2.700 nmi. A 27-inch monitor is 68.58 cm. A 550 nm optical wavelength is 0.00055 mm.
Related: Weight converter · Unit converter · Engineering unit converter
Frequently asked questions
Is the length converter based on meters?
Yes. All units are gathered into meters, then divided again. Miles and nautical miles also use meter factors. Metric is the default; yard-pound units are attached only as factors. For legal metrology certificates, use a national standard table.
What are the mile and nmi conversion factors?
1 mile = 1609.344 m, 1 nmi = 1852 m. Nautical miles are used in navigation and aviation and are longer than statute miles. Mixing land and sea distance can be off by several kilometers. Distinguish mile and nmi in the unit list.
Does the length converter also do cm–inch?
Yes. Choose centimeter or inch as the starting unit and the rest appear together. 1 in = 2.54 cm. Starting from inches also shows feet and yards, which helps match drawing dimensions.
Are nanometers (nm) supported?
Yes. Micrometers (µm) and nanometers (nm) are in the list. Use them for wavelength and process-scale conversion. Nanometers often show scientific notation. If that is hard to read, switch to micrometers.
Do weight or power work on this screen?
No. Use the weight, power, and engineering unit converters. Pressure in psi or mass in kg belong on the engineering or weight converters. This table covers length only.
Does the value update as I type?
Yes. Recalculation happens as soon as you type a value or change the unit. Clicking Convert does the same. Because it runs on each input event, the table can update while you are still deleting digits.
Last reviewed: 2026-09-04