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Unit Converter

Convert between units of length, weight, temperature, area, volume, speed, and data.

About This Tool

The Unit Converter is a free online tool that instantly converts between units across 7 measurement categories: length, weight, temperature, area, volume, speed, and digital data. Whether you need to convert miles to kilometers for a road trip, Fahrenheit to Celsius for a recipe, or megabytes to gigabytes for storage planning, this tool handles it all in one place.

All conversions run entirely in your browser — no data is sent to any server. The tool uses precise conversion factors and handles temperature conversions (which require formulas, not just ratios) correctly for Celsius, Fahrenheit, and Kelvin. Results in scientific notation are shown when values are extremely large or small.

How to Use

  1. Select a measurement category (Length, Weight, Temperature, etc.) from the tab bar.
  2. Choose the unit to convert from in the left dropdown.
  3. Enter the value you want to convert.
  4. Choose the unit to convert to in the right dropdown.
  5. The result updates instantly. Click the ⇆ button to swap the two units.

Use Cases

Developers use the data category to convert between bytes, KB, MB, and GB when working with file sizes and APIs. Engineers and scientists use length and area conversions between metric and imperial systems. Travelers convert speed (mph to km/h) and temperature (°F to °C) when visiting countries with different measurement standards. Chefs and home cooks rely on volume conversions between teaspoons, cups, and liters.

FAQ

  • How many unit categories are supported? — 7 categories: length, weight, temperature, area, volume, speed, and digital data.
  • Why does temperature conversion work differently? — Temperature uses formulas (not just ratios) because Celsius and Fahrenheit have different zero points.
  • What is the most precise conversion? — All conversions use JavaScript's 64-bit floating point arithmetic. Results beyond 10 significant digits may have rounding errors.
  • Can I convert between metric and imperial? — Yes. All categories include both metric (SI) and imperial/US customary units.