Unit Converter

Free Online Unit Converter: Metric, Imperial & Scientific

Looking for a free online unit converter that actually covers everything? Our comprehensive conversion tool is designed for students, engineers, and DIY enthusiasts who need instant, high-precision results. Whether you are switching between Metres (m) and Feet (ft) for a home project or converting Pascals (Pa) to Bar for industrial engineering, our engine handles it all in real-time.

Why use this Free Conversion Tool?

Most online calculators are limited to basic weight and length. This tool goes further, offering a massive library of units across 16 distinct categories. From common Kilogrammes (kg) and Pounds (lb) to more obscure measures like Barleycorns, Leagues, and Cubits, we provide a one-stop shop for every possible measurement. Best of all, it is completely free to use with no registration required.

How do I convert between different units?

1. Select your category: Use our table of contents to jump straight to Distance, Weight, Volume, or specialised fields like Radiation and Kinematic Viscosity.
2. Input your value: Type any number into your known unit field. For example, enter '1' into Litres (l).
3. Instant results: The tool automatically calculates the equivalent across all other units in that group, such as UK Pints, US Gallons, and Cubic Metres (m³).
4. Customise Precision: Use the slider to adjust your results from 0 up to 10 decimal places—perfect for when scientific accuracy is non-negotiable.

Common Conversions and Supported Units

Our tool is built to handle everyday queries as well as complex scientific data. Here is a breakdown of what you can convert right now:

• Length & Distance: Instantly convert Kilometres (km) to Miles (mi), Centimetres (cm) to Inches (in), or explore historical units like Spans, Palms, and Digits.
• Weight & Mass: Move between Metric Tonnes, Stone (st), Grammes (g), and Milligrammes (mg). We even include Carats for jewellers and gemologists.
• Temperature: Easily switch between Celsius (°C), Fahrenheit (°F), and Kelvin (K).
• Digital Data: Essential for IT professionals; convert Megabytes (MB) and Gigabytes (GB) to Terabytes (TB) or Kibibytes (KiB).
• Energy & Power: Calculate Joules (J) to Calories, or Watts (W) to both Metric and Imperial Horsepower.
• Specialised Science: We support Newtons (N) and Dynes for force, Hertz (Hz) and RPM for frequency, and even Sieverts (Sv) and Becquerels (Bq) for radioactivity.

What makes our tool better than others?

Unlike basic converters, we prioritise the user experience with features like one-click copying to your clipboard and a live search bar to help you find units like Knots, Mach, or Lux instantly. Our 'Expand All' and 'Collapse All' buttons keep the interface clean, making this the most efficient free online converter for desktop and mobile. Whether you're dealing with Atmospheres (atm), PSI, Gradians, or Radians, our logic ensures your data remains reliable and precise.

Is this tool suitable for professional use?

While we avoid the 'professional' price tag by keeping this tool free, the logic is anything but basic. With support for Stokes and Centistokes in viscosity, Foot-candles in light, and Poundals in force, it is robust enough for technical documentation, academic research, and complex engineering tasks. If you need a fast, free online solution for Square Metres (m²) to Acres or Hectares, you’ve found it.