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What Is the Unit Converter?

The unit converter is a free online tool that converts values between measurement units across 7 categories: length, weight and mass, temperature, area, volume, speed, and data storage. It covers metric (SI), imperial, and US customary systems, from everyday conversions like miles to kilometers to technical ones like mebibytes to gigabytes.

Select a category, choose your source and target units, enter a value, and the result appears instantly. The swap button lets you reverse the conversion, and the full table below shows how the input converts to every unit in the category at once.

How to Use the Unit Converter

1. Click a category tab (Length, Weight, Temperature, etc.).
2. Select the From unit using the dropdown.
3. Select the To unit using the second dropdown.
4. Enter your value in the input field — the result updates instantly.
5. Click ⇄ to swap the two units and reverse the conversion.
6. Scroll down to see conversions to all units in the category at once.

Features

• 7 measurement categories: Length, Weight, Temperature, Area, Volume, Speed, Data
• Covers metric, imperial, and US customary units
• Instant real-time conversion as you type
• Swap button to reverse source and target units
• Full conversion table showing all units in the selected category
• Up to 10 significant digits of precision with automatic scientific notation
• Runs entirely in your browser — no data sent to servers

FAQ

What unit categories does the converter support?

The converter supports 7 categories: Length (mm to nautical miles), Weight/Mass (mg to US tons), Temperature (Celsius, Fahrenheit, Kelvin), Area (mm² to square miles), Volume (ml to US gallons), Speed (m/s to Mach), and Data Storage (bits to terabytes).

How accurate are the conversions?

Conversions use standard international definitions. For example, 1 inch = exactly 0.0254 meters, 1 pound = exactly 0.45359237 kg. Results are shown to up to 10 significant digits.

Can I see all conversions at once?

Yes. After entering a value, the tool shows a table with conversions to every unit in the selected category at the same time.

How do I convert Celsius to Fahrenheit?

Select the Temperature category, choose Celsius as the "From" unit and Fahrenheit as the "To" unit, then enter your value. The formula used is: °F = °C × 9/5 + 32.