Length Converter
Runs locally in your browser. Nothing leaves your device.Enter one length and instantly convert it to metres, inches, feet, miles, nautical miles, and astronomical units.
Use a comma or period as the decimal separator; do not use thousands separators.
All units
Metric & scientific
Imperial & navigation
Astronomy
How it works
- 1
Enter value and source unit
Enter the length value and choose the source unit via search or group list.
- 2
Choose the target unit
Choose the target unit from one of the three groups or from recently used units.
- 3
Copy the result or swap units
Copy a single result or all results at once, or swap the source and target unit for the next conversion.
Good to know
The length converter converts directly in your browser between three unit groups: Metric & scientific, Imperial & navigation, and Astronomy. A unit search and a list of recently used units help you find the right unit quickly even with many options.
Calculation runs locally in the browser. Astronomical units such as light-year or astronomical unit are meant for orders of magnitude, not for survey-grade precision.
Typical use cases
Everyday conversions
Convert meters to feet, centimeters to inches, or kilometers to miles, for example for travel, furniture dimensions, recipes, or product specs.
Navigation and nautical distances
Use the Imperial & navigation group for nautical-mile-based distances when you need to convert nautical or aviation figures into metric units.
Put astronomical scales into perspective
Convert light-years, astronomical units, or parsecs into kilometers to make distances from astronomy texts or science articles tangible.
Tips for better results
Pick the right group instead of similarly named units
Metric & scientific, imperial & navigation, and astronomy are grouped separately so you don't accidentally pick a similarly named but wrong unit from another group.
Use unit search when there are many options
Type the unit name into the search instead of scrolling a long list; recently used units are also suggested separately.
Features
Three grouped unit categories
Metric & scientific, imperial & navigation, and astronomy are cleanly separated.
Local conversion
Calculation happens directly in the browser, without transmission to a server.
Search, recent units, and notation
Find units via search or from the list of recently used units, and choose decimal or scientific notation with adjustable precision.
Frequently asked questions
What unit groups are available?
Metric & scientific, imperial & navigation, and astronomy.
How accurate are astronomical units like light-year?
They are meant for orders of magnitude and comparisons, not for survey-grade binding precision.
Are my inputs uploaded?
No. Conversion runs entirely locally in the browser.
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