How the unit converter works
Choose a category, enter a value and pick the units to convert from and to. The result appears instantly, along with the conversion factor and a table showing your value in every unit of that category. Use the Swap button to reverse the conversion. Behind the scenes every unit is defined by its exact size in a base unit (metres, kilograms, square metres, litres or metres per second), so any unit can be converted to any other in the same category with one multiplication and one division.
The conversion method in plain words
Result = value × (size of "from" unit ÷ size of "to" unit)
Temperature is the exception, because the scales start at different zero points. The calculator converts through Celsius using these formulas:
°F = °C × 9 ÷ 5 + 32 °C = (°F − 32) × 5 ÷ 9 K = °C + 273.15
Worked examples
- 5 kilometres to miles: 5 × 1,000 ÷ 1,609.344 = 3.107 miles
- 37 °C to Fahrenheit: 37 × 9 ÷ 5 + 32 = 98.6 °F (normal body temperature)
- 1 acre to square feet: 43,560 sq ft; 1 cent is 435.6 sq ft and 1 guntha is 1,089 sq ft
- 1 tola to grams: 11.66 g
Indian units included
Alongside metric and imperial units, the converter includes units still widely used in India: tola and quintal for weight, and gaj (square yard), cent and guntha for land area. Local land units such as bigha vary from state to state, so they are not included; check the local definition before converting them.
Tips for accurate conversions
- US and UK gallons are different: a US gallon is 3.785 litres, a UK gallon is 4.546 litres.
- Cups, tablespoons and teaspoons here are US kitchen measures; recipes from other countries may differ slightly.
- Very small or very large results are shown in scientific notation, for example 1.5e-7.
- Temperatures below absolute zero (−273.15 °C) are not physically possible, so the converter will tell you if you enter one.
Frequently asked questions
How do I convert km to miles?
Divide kilometres by 1.609344, or multiply by about 0.6214. For example, 10 km is about 6.21 miles.
How do I convert Celsius to Fahrenheit?
Multiply by 9, divide by 5 and add 32. 30 °C is 30 × 9 ÷ 5 + 32 = 86 °F.
How many square feet are in an acre?
One acre is exactly 43,560 square feet, or about 4,046.86 square metres. It also equals 100 cents or 40 guntha.
How many grams are in a tola?
One tola is 11.6638 grams. Ten grams of gold is therefore about 0.857 tola.
What is a gaj?
Gaj is the common Indian name for a square yard, used for plot sizes in many states. One gaj equals 9 square feet or about 0.836 square metres.
Is this converter accurate?
Yes. It uses the exact international definitions of each unit (for example 1 inch = 2.54 cm and 1 pound = 0.45359237 kg) and shows up to 6 decimal places.