Unit Converter
Convert between units of length, weight, temperature, area, volume, and speed. Fast, accurate, and free.
What Is Unit Conversion?
Unit conversion expresses a measurement in a different unit of the same physical quantity. The same length can be expressed in metres, feet, miles, or light years; the same temperature in Celsius, Fahrenheit, or Kelvin; the same weight in kilograms, pounds, or ounces. Different regions, disciplines, and industries use different measurement systems — most notably the metric (SI) system used in most of the world and the imperial system used primarily in the United States.
Errors in unit conversion have caused real-world disasters. In 1999, the Mars Climate Orbiter was lost because one engineering team used metric units and another used imperial units with no conversion performed between them. This incident illustrates why reliable, automatic unit conversion is important anywhere measurements from different systems are combined.
When You Need to Convert Units
Unit conversion is a constant need across everyday life and professional work. Cooking and baking recipes may specify quantities in cups, millilitres, ounces, or grams depending on their country of origin. Construction and DIY projects require converting between feet, metres, and square units for material estimates. Medical dosing calculations convert between milligrams, micrograms, and millilitres. Travel between countries requires converting speeds, temperatures, and fuel volumes.
Developers working with APIs frequently encounter unit conversion when integrating data from international sources — a weather API might return temperature in Kelvin, a mapping API might return distances in miles or kilometres depending on locale, and a fitness API might switch between metric and imperial based on user settings. A reliable unit converter eliminates arithmetic errors and ensures consistent precision.
How to Use Unit Converter
- 1
Select a measurement category from the tabs (Length, Weight, Temperature, etc.).
- 2
Choose the unit you are converting from and enter the value.
- 3
Select the target unit in the "To" dropdown.
- 4
The result appears instantly. Use "Swap" to reverse the conversion.
Frequently Asked Questions
How do I convert meters to feet?
Open the Unit Converter, select Length, choose Meters as the From unit and Feet as the To unit, then enter your value. The result appears instantly.
How do I convert Celsius to Fahrenheit?
Select Temperature in the Unit Converter, choose Celsius as From and Fahrenheit as To, enter the temperature. The converter uses the exact formula: °F = (°C × 9/5) + 32.
Does the unit converter work for metric and imperial?
Yes. It supports both metric (meters, kilograms, liters) and imperial (feet, pounds, gallons) units across all six categories.