Unit ConverterUnit Converter — Everyday & Scientific Units

A converter for the measurements you use

Choose from 28 categories: length, area and Indian land, mass, volume and cooking, time, temperature, temperature change, speed, pressure, energy, power, angle, digital storage, data transfer rate, frequency, fuel economy, force, torque, density, volume flow rate, acceleration, electric current, electric charge, voltage, resistance, capacitance, dynamic viscosity and kinematic viscosity.

Start with one of the quick examples or select a category. Enter your value, search for a unit by its name or symbol, and choose the source and destination units. Length and mass also offer paired feet+inches and kg+g input. Open the selected formula and definitions or compare the same value in every available unit. Copy the selected result to use it elsewhere.

Mixed input and technical quantities

For feet+inches, enter whole feet and inches from zero to below 12. For kg+g, enter whole kilograms and grams from zero to below 1,000. The smaller part can contain decimals. One blank part counts as zero; two blank parts leave the result empty. Use Single value for negative measurements or a fractional larger part. Switching back preserves an exact supported total in inches or grams; if that cannot fit the supported input, the value is cleared with an explanation.

The electrical categories keep current, charge, voltage, resistance and capacitance separate. 1 Ah is exactly 3,600 C and 1 mAh is 3.6 C. A battery's mAh cannot be converted to Wh without voltage. Electrical prefixes are decimal powers of ten.

Standard gravity is the fixed convention 9.80665 m/s²; gravity at a real location can differ. Gal means centimetres per second squared. Dynamic viscosity uses Pa·s; kinematic viscosity uses m²/s. Changing between the two needs the fluid's density under the same conditions. The converter changes units, not viscosity grades, cup timings or a material's behaviour. Signed entries are mathematical conversions rather than certification of physical properties.

Indian land units with fixed definitions

The land conversions use the international foot: 1 foot is exactly 0.3048 metres. An acre is exactly 43,560 square feet, or 4,046.8564224 square metres. A cent is one-hundredth of an acre; a guntha is one-fortieth. The square yard (gaj) is exactly 9 square feet.

Bigha, biswa and other land measures that vary by place are excluded. Get the local square-foot or square-metre definition before converting a figure in those units. Converting an area also does not change what was measured: carpet area and built-up area remain different quantities.

• 1 acre = 43,560 square feet = 4,840 square yards = 100 cents = 40 guntha.
• 1 cent = 435.6 square feet = 40.468564224 square metres.
• 1 guntha = 1,089 square feet = 101.17141056 square metres.
• 1 hectare = 10,000 square metres; the corresponding acre value is rounded when displayed.

Choose the definition that matches your measurement

US liquid gallons and imperial gallons are different sizes: exactly 3.785411784 litres and 4.54609 litres respectively. Recipes also use different cups and spoons. The choices identify a US customary cup, a 240 mL nutrition-label cup, a 250 mL metric cup, and tablespoons of 15 or 20 mL. Keep the recipe's convention consistent.

Digital units need the same care. A byte contains 8 bits. Decimal kilobytes, megabytes and gigabytes use powers of 1,000; binary kibibytes, mebibytes and gibibytes use powers of 1,024. The labels and symbols make the distinction visible: MB differs from MiB, and Mbit/s differs from MB/s.

Mass, force, energy and power are separate categories. A kilogram measures mass, a newton measures force, a kilowatt-hour measures energy, and a kilowatt measures power. Converting between those quantities would require more information than a unit factor.

Temperature readings, temperature changes and fuel mileage

A thermometer reading uses an offset: Celsius to Fahrenheit is °F = °C × 9/5 + 32. A temperature change uses only the scale factor, so a rise of 10 °C is a rise of 18 °F. Use the separate Temperature change category for differences, including falls shown as negative values. Absolute temperature readings below 0 kelvin are rejected.

Fuel efficiency and fuel consumption are inverses. For example, 20 km/L equals 5 L/100 km. Doubling the efficiency halves the consumption. All fuel entries must be greater than zero, and US and imperial miles per gallon are separate choices.

Time conversions use fixed durations: a day is 24 hours and a week is 7 days. The year choices explicitly specify 365 or 365.25 days. A calendar month or elapsed time between dates needs a calendar calculation; it cannot be converted using one universal multiplier.

Precision you can see and control

Entered decimals and standard decimal unit definitions are kept as exact fractions during the calculation. The result is rounded once, for display, using your chosen 6 to 24 significant digits. The ≈ symbol marks a rounded result or a conversion involving an approximate constant. Exact unit relationships stay exact even when an earlier display would have rounded their factors.

Conversions involving radians, angular frequency or parsecs can require π. The converter evaluates π to 50 decimal places and labels these conversions. Shared π factors cancel for direct conversions such as degrees to arcminutes. Mercury and water pressure columns use the conventional definitions stated in their labels; they do not model the properties of a real fluid column at another temperature.

Scientific notation keeps very small or large numbers readable. For example, 1e-6 means 0.000001. Nonzero values are never rounded silently to zero. Inputs can contain correctly grouped Western or Indian commas, and may be up to 240 characters long. Nonzero inputs and results must have a magnitude of at least 1e-300 and below 1e301, with entered exponents between -300 and 300. Values outside this supported range show a clear error.

Extra digits describe the conversion, not the accuracy of the measurement you started with.