Free Unit Converter - Length, Weight, Temperature & More

Convert units of length, weight, temperature, speed, volume, pressure and energy instantly. Free online unit conversion tool with real-time results.

What Is Unit Converter?

Unit conversion is the process of changing a measurement from one unit to another — kilometres to miles, kilograms to pounds, Celsius to Fahrenheit. While the maths is straightforward, keeping track of conversion factors across dozens of unit types is impractical, especially for less common conversions like nautical miles to metres or troy ounces to grams.

This converter covers all the major measurement categories: length, weight, temperature, volume, area, speed, pressure and more. It handles the calculation instantly and accurately, including temperature conversions which use formulas rather than simple multiplication factors.

How to Use This Tool

  1. Select the measurement category (length, weight, temperature, etc.).
  2. Choose the unit you are converting from in the first dropdown.
  3. Choose the unit you are converting to in the second dropdown.
  4. Enter the value you want to convert.
  5. The result updates instantly as you type.

Tips & Best Practices

  • For temperature, remember that Celsius to Fahrenheit is not a simple ratio — it uses the formula (°C × 9/5) + 32.
  • Use metric prefixes consistently: kilo (1,000), mega (1,000,000), milli (0.001), micro (0.000001).
  • When converting cooking measurements, note that US and UK fluid ounces differ slightly (29.57ml vs 28.41ml).
  • Swap the "from" and "to" units to quickly reverse a conversion.

Common Use Cases

  • Converting recipe measurements between metric and imperial units.
  • Translating foreign product specifications into familiar units.
  • Solving physics, chemistry or engineering problems that involve multiple unit systems.
  • Converting dimensions for international shipping, travel or construction projects.

Frequently Asked Questions

What units can I convert?

The tool supports 7 categories: length (mm to miles), weight (mg to tonnes), temperature (Celsius, Fahrenheit, Kelvin), speed, volume, pressure and energy.

How do I convert Celsius to Fahrenheit?

Select the Temperature category, enter your value in Celsius, and the Fahrenheit result updates instantly. The formula is F = C x 9/5 + 32.

Is the unit converter accurate?

Yes. All conversions use precise mathematical factors. Temperature conversions use the exact formulas rather than approximate values.