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Unit Converter

Convert length, weight, temperature, area, volume, speed, and data units.

Millimetre (mm)1
Centimetre (cm)0.1
Metre (m)0.001
Kilometre (km)1.0000e-6
Inch (in)0.0393701
Foot (ft)0.00328084
Yard (yd)0.00109361
Mile (mi)6.2137e-7
Nautical mile5.3996e-7

Unit conversion categories

  • Length — mm, cm, m, km, inch, foot, yard, mile, nautical mile
  • Weight — mg, g, kg, tonne, ounce, pound, stone
  • Temperature — Celsius, Fahrenheit, Kelvin
  • Area — mm², cm², m², km², in², ft², acre, hectare
  • Volume — mL, L, m³, fl oz, cup, pint, quart, gallon
  • Speed — m/s, km/h, mph, knot, Mach
  • Data — bit, byte, KB, MB, GB, TB

Quick reference conversions

  • 1 inch = 2.54 cm
  • 1 kg = 2.205 lbs
  • 1 mile = 1.609 km
  • 1 litre = 0.264 US gallons
  • 100°C = 212°F = 373.15 K
  • 1 GB = 1,024 MB = 8,589,934,592 bits

Common use cases for unit conversion

Engineers reviewing international specifications convert between SI and imperial units daily — a machine spec in inches needs to be quoted in millimetres for a European supplier. Nutritionists and home cooks convert between grams and ounces when following recipes from different countries. Developers checking storage and bandwidth requirements convert between megabytes, gigabytes, and bits when evaluating API limits or file transfer times. Students sitting for physics or chemistry exams need to convert between m/s and km/h, or between litres and cubic metres, without making factor-of-1000 errors.

Tips for accurate unit conversion

Always confirm which definition of a unit is in use — a US gallon (3.785 L) and an imperial gallon (4.546 L) are meaningfully different for fuel efficiency comparisons. For data storage, confirm whether the context uses IEC binary prefixes (1 KB = 1,024 bytes) or SI decimal prefixes (1 KB = 1,000 bytes) — hard drive manufacturers use decimal, operating systems traditionally use binary. For temperature, Kelvin is the only unit used in scientific calculations (thermodynamic equations break at negative values); always convert to Kelvin before applying physics formulas.

Who uses a unit converter regularly

Indian import/export professionals convert between metric and imperial when filing customs declarations for goods measured in foreign units. Fitness enthusiasts compare their weight across countries — kg in India vs lbs in the US — when tracking progress on international apps. Travel bloggers convert local speed limits (km/h in Europe, mph in the US and UK) to make trip-planning guides accessible to international readers. Software engineers calculate bandwidth, latency, and storage in different orders of magnitude depending on whether they are discussing network traffic (Mbps), disk space (GB/TB), or memory (KB/MB).

Frequently asked questions

How do I convert Celsius to Fahrenheit?
Select the Temperature category, choose Celsius input unit, and enter your value. The converter shows the equivalent in Fahrenheit and Kelvin instantly. Formula: °F = (°C × 9/5) + 32.
How many kg in a pound?
1 pound = 0.453592 kg. Conversely, 1 kg = 2.20462 pounds. Select the Weight category to convert between all weight units at once.
How do I convert km to miles?
1 kilometre = 0.621371 miles. 1 mile = 1.60934 km. Select the Length category, choose Kilometre , and the converter shows miles and all other length units.
What data units are supported?
The Data category supports bits, bytes, kilobytes (KB), megabytes (MB), gigabytes (GB), and terabytes (TB). All conversions use binary definitions (1 KB = 1024 bytes).
Why does my conversion show scientific notation?
Very large or very small values are displayed in scientific notation (e.g., 1.23e+9) to keep the display clean. This happens when converting between units with very large conversion factors, like bits to terabytes.

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