Unit Conversion
Length, weight, temperature, area, volume, speed, and energy — convert between any units in metric, imperial, and Indian systems, instantly and accurately.
Unit conversion calculators across length, weight, temperature, area, volume, and speed — supporting metric, imperial, and Indian-specific units (lakh, crore, sq ft, sq yard, sq metre). Every conversion uses the exact NIST-published factor, not approximations.
Conversion
Length Converter
Convert between metres, kilometres, miles, feet, inches, yards, and nautical miles — instant, accurate metric ⇄ imperial conversion with full precision.
Open calculatorWeight Converter
Convert weight units — milligrams, grams, kilograms, pounds, ounces, stones, and metric tons — for cooking, shipping, fitness, and global trade.
Open calculatorTemperature Converter
Convert between Celsius, Fahrenheit, Kelvin, and Rankine — the four temperature scales used in weather, cooking, scientific research, and engineering work.
Open calculatorArea Converter
Convert area units — square metres, hectares, acres, square feet, square yards, square miles — for property, land, agriculture, and construction estimation.
Open calculatorSpeed Converter
Convert speed units — kilometres per hour, miles per hour, metres per second, knots, and feet per second — for vehicles, aviation, sport, and physics.
Open calculatorVolume Converter
Convert volume units — litres, millilitres, gallons (US/UK), cubic metres, fluid ounces, cups, tablespoons — for cooking, fuel, chemistry, and trade.
Open calculatorWhat you can convert
Length (m, cm, mm, km, in, ft, yd, mi), weight (kg, g, mg, lb, oz, ton, quintal), temperature (°C, °F, K), area (sq m, sq ft, sq yd, acre, hectare, gunta, bigha — including Indian land-area units), volume (l, ml, m³, gal, cup, oz), and speed (km/h, m/s, mph, knots, ft/s).
All conversion factors come from the NIST Special Publication 811 (the international standard reference) or the relevant ISO standards. Indian land-area conversions (gunta, bigha, acre to sq ft) use state-by-state values where they differ — Maharashtra bigha vs UP bigha for example.
Frequently asked questions
Why do bigha conversions differ by state?
'Bigha' is a regional Indian land area unit with different values in different states. UP/Bihar bigha is 27,225 sq ft. Bengal bigha is 14,400 sq ft. Punjab bigha is 9,070 sq ft. Madhya Pradesh bigha is 12,000 sq ft. The area conversion calculator uses the most common state values; cross-check with the local revenue department for transactions.
Are these conversions exact?
Yes for SI-defined units (meter, kilogram, second). Imperial units defined relative to SI (1 inch = 25.4 mm exactly) are also exact. Customary units that have multiple definitions (US vs UK gallon, regional bigha) use the most common standard with the alternative noted.
How do I convert temperature accurately?
°C to °F: multiply by 9/5 and add 32. °F to °C: subtract 32, multiply by 5/9. K to °C: subtract 273.15. The temperature converter handles all three scales and shows both the formula and result.
Explore other categories from Calculatorist's home page, or jump straight to one of the most popular calculators below.