Unit Converter

How the converter works

Every unit in a category is stored as a multiple of one base unit — metres for length, kilograms for weight, square metres for area, litres for volume, metres per second for speed, bytes for data and seconds for time. Converting from unit A to unit B is then a single step:

value in B = value in A × (factor of A ÷ factor of B)

For example, 5 miles to kilometres: 5 × 1609.344 m ÷ 1000 m = 8.04672 km. Because there is only one multiplication and one division, rounding errors do not stack up, and the table below the result shows the same value in every unit of the category at once.

Temperature is the exception because its scales do not start at the same zero. The converter uses the standard formulas: °F = °C × 9/5 + 32, K = °C + 273.15, and the reverse of each.

Indian units you will find here

• Tola: 11.6638 g, the weight jewellers use for gold and silver. 10 g of gold is about 0.857 tola, so a “1 tola” coin is a bit heavier than a 10 g one.
• Bigha: not a fixed unit. It is roughly 1,600 sq yd (1,337.8 m²) in West Bengal, Assam and parts of Uttarakhand, about 1,011 m² in Punjab and Haryana, and up to 2,529 m² (27,000 sq ft) in Uttar Pradesh and Bihar. This tool uses the 1,600 sq yd value; for a land deal, confirm the local definition with the registrar or the sale deed.
• Gunta (guntha): 101.17 m², or 1/40 of an acre, used in Maharashtra, Karnataka and Andhra Pradesh.
• Cent: 40.47 m², or 1/100 of an acre, common in Tamil Nadu and Kerala.
• Square yard (gaj): 0.836 m². Plot sizes in Delhi NCR, Punjab and Rajasthan are usually quoted in gaj.

Handy reference values

KB vs KiB: why your 1 TB drive shows 931 GB

Hard-drive and SSD manufacturers use decimal prefixes (1 TB = 10¹² bytes). Windows reports sizes in binary multiples (1 TiB = 2⁴⁰ bytes) but labels them “TB”. The difference is about 7% at the gigabyte level and 10% at the terabyte level. Choose the KiB/MiB/GiB units when you want to match what your operating system displays.

Tips

• Type in either box. Both fields are live, so you can work backwards from a target value.
• Use the swap button to flip the direction without retyping.
• Results are rounded to six significant digits, which is enough for engineering drawings, recipes and land records alike. Very large values are shown as whole numbers.
• Speed conversions are helpful for aviation and sailing, where knots are standard, and for comparing car speed limits abroad (65 mph ≈ 105 km/h).
• Months and years in the Time category are averages (30.44 and 365.25 days); use the date difference calculator when you need exact calendar spans.

Frequently asked questions