Length Unit Converter
Professional length unit converter supporting fast conversion between kilometers, meters, centimeters, millimeters, micrometers, inches, feet, yards, miles, Chinese li/zhang/chi/cun and more.
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How to use the Length Unit Converter
This tool converts between metric units (kilometer, meter, centimeter, millimeter, si), microscopic units (micrometer, nanometer, picometer), imperial units (inch, foot, yard, mile, nautical mile, fathom, furlong, mil) and traditional Chinese units (li, zhang, chi, cun, fen, li, hao). All conversions run entirely in your browser with no server requests, making it suitable for engineering design, mechanical manufacturing, UI layout, map measurement and daily-life conversions.
- Type a value into any unit input (decimals are supported). The value is interpreted as a distance in that specific unit.
- Once you finish input, all other unit fields are updated with converted values so you can easily compare metric, imperial and Chinese systems.
- Inputs must be numbers greater than or equal to 0. When the input is empty or invalid, other fields are cleared to avoid confusion.
- Internally the converter uses meters (m) as the base unit. For example: 1 kilometer = 1000 meters, 1 mile = 1609.344 meters, 1 chi ≈ 0.333333 meters, 1 inch = 2.54 centimeters, etc.
- For very large or very small values, the converter automatically switches between normal decimals and scientific notation to balance precision and readability.
FAQ
Why are some results shown in scientific notation?
When distances are extremely large or small, showing them purely as decimals makes them hard to read and may lose meaningful digits. The converter uses scientific notation in those extreme ranges to keep results both readable and precise.
Which conversion rules are used for Chinese units such as li, zhang, chi and cun?
This tool uses a commonly adopted modern convention, for example: 1 li = 500 meters, 1 zhang ≈ 3.333333 meters, 1 chi ≈ 0.333333 meters, 1 cun ≈ 0.033333 meters, etc. Historical values may vary by period and region, so for rigorous research you should refer to domain-specific standards.
In which scenarios are nautical miles, fathoms and furlongs used?
Nautical miles (nmi) are widely used in marine and aviation navigation; fathoms are primarily used for water depth; furlongs appear in horse racing and some traditional contexts. This converter lets you conveniently switch between those units and metric meters/kilometers.
Can I rely on these results for construction drawings or precision manufacturing?
The converter uses JavaScript floating point arithmetic with rounded display values, which is suitable for planning and everyday calculations. For actual construction, machining or inspection, you should rely on professional CAD software outputs and calibrated measurement tools.