Convert length, weight, temperature, speed, area, volume, pressure, energy and more — all in one place.
A unit conversion calculator is an all-in-one tool that transforms measurements from one unit to another across multiple physical quantity categories. Different countries, scientific disciplines, and industries use different measurement systems — the metric system (SI), the imperial system, and various specialized units. A comprehensive unit converter eliminates the need for manual lookup tables and complex calculations.
Calculator Expert's Unit Conversion Calculator covers 10 major categories — Length, Weight, Temperature, Speed, Area, Volume, Pressure, Energy, Data Storage, and Time — making it the only conversion tool you need for everyday and professional use.
Length: 1 inch = 2.54 cm, 1 mile = 1.609 km, 1 foot = 0.3048 m. Weight: 1 kg = 2.2046 lbs, 1 oz = 28.35 g. Speed: 1 km/h = 0.6214 mph, 1 knot = 1.852 km/h. Area: 1 acre = 4,047 m², 1 hectare = 2.471 acres. Volume: 1 litre = 0.2642 US gallons, 1 cup = 240 ml. Pressure: 1 atm = 101,325 Pa = 14.696 psi. Energy: 1 calorie = 4.184 joules, 1 kWh = 3,600,000 joules.
Engineers converting between metric and imperial specifications. Scientists working with SI units in international collaborations. Students solving physics and chemistry problems requiring unit conversions. Chefs converting recipe measurements between US cups and metric grams/ml. Travellers converting miles to km, Fahrenheit to Celsius. IT professionals converting data sizes between bytes, KB, MB, GB. Doctors converting patient weights and measurements between different systems. Architects working across different international building codes.
The metric (SI) system is used by over 95% of the world and is based on powers of 10, making it easy to scale (milli = 1/1000, kilo = 1000). The imperial system, used primarily in the USA (and partially in the UK), uses historically derived units with irregular relationships (12 inches = 1 foot, 3 feet = 1 yard, 1760 yards = 1 mile). India officially uses the metric system but many traditional units (bigha, tola, maund) remain in use for specific contexts.
The International System of Units (SI) has 7 base units from which all other units are derived: Meter (length), Kilogram (mass), Second (time), Ampere (electric current), Kelvin (temperature), Mole (amount of substance), Candela (luminous intensity). All other units — like Newton, Joule, Pascal, Watt — are derived combinations of these 7 base units. Understanding this hierarchy helps in navigating complex conversions in physics and engineering.
Click a category pill at the top to select the type of unit you want to convert (e.g., Length, Weight, Temperature). Enter your value in the input field. Select the "From" unit and the "To" unit from the dropdowns. Click Convert — the result appears with a full expression. Use the Swap button to quickly reverse the conversion. The quick-reference grid below shows the input value converted to all available units at once.
Temperature conversion is non-linear and handled separately — values below absolute zero (−273.15°C or 0 K) are physically invalid. Some specialized or regional units are not included. Currency conversion is not available as exchange rates change in real time — use a dedicated currency converter for that. Very large or very small numbers may display in scientific notation. The tool uses standard international conversion factors; minor rounding differences may exist at very high decimal precision.