Unit converter
Convert between 100+ units in eleven categories. Pick a category, type a value, and every result updates as you type. Factors are exact wherever a legal definition exists.
1 centimetre in every length unit
Converters by category
- Length Converter
- Weight Converter
- Temperature Converter
- Volume Converter
- Area Unit Converter
- Speed Converter
- Time Converter
- Data Storage Converter
- Pressure Converter
- Energy Converter
- Angle Converter
Popular conversions
How unit conversion works
Every category has one base unit (the metre, kilogram, litre, pascal…). Each other unit is stored as “how many base units it equals”. To convert, multiply by the from factor to reach the base unit, then divide by the to factor.
Example: 5 feet to centimetres. 1 ft = 0.3048 m and 1 cm = 0.01 m, so 5 × 0.3048 ÷ 0.01 = 152.4 cm.
Squared and cubed units square or cube the factor: 1 ft² = 0.3048² = 0.09290304 m², and 1 ft³ = 0.3048³ ≈ 0.0283 m³. Forgetting this is the most common mistake in area and volume conversions.
Questions people ask
Which unit categories does the converter cover?
Eleven: length, weight (mass), temperature, volume, area, speed, time, data storage, pressure, energy and angle, with more than 100 units in total.
Are the conversion factors exact?
Where a definition exists they are exact: the inch is 2.54 cm, the pound 0.45359237 kg, the US gallon 3.785411784 L, the standard atmosphere 101,325 Pa. Values follow NIST Special Publication 811 and the SI Brochure. Results are displayed to 10 significant digits.
Why is temperature different from other conversions?
Celsius and Fahrenheit have different zero points, so you cannot convert them with one multiplier. The converter goes through kelvin: it shifts to absolute zero, scales, then shifts back.
Why does my 1 TB drive show about 931 GB?
Drive makers use decimal terabytes (10¹² bytes). Windows reports binary units (2⁴⁰ bytes per TiB) but labels them GB/TB. 10¹² ÷ 2³⁰ ≈ 931.3 GiB. Pick GB and GiB in the Data converter to see both.
Does it work offline?
Once the page has loaded, every conversion is computed in your browser, so it keeps working without a connection.