Unit Converter

How Unit Converter works

Convert length, weight, temperature, area, speed and data units with instant, accurate results. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

How the conversion is done

Every unit in a category is defined as a multiple of one base unit — metres for length, kilograms for weight, litres for volume, bytes-per-million for data. Converting is then two multiplications: value × factor of the source unit, divided by the factor of the target.

That design is why the tool shows every unit in the category at once instead of one pair: the arithmetic is the same for all of them, so there is no reason to hide the rest.

Exact factors and defined constants

Some conversions are exact by definition, not measurement. An inch is exactly 25.4 millimetres. A pound is exactly 0.45359237 kilograms. A mile is exactly 1609.344 metres. A nautical mile is exactly 1852 metres. A US gallon is exactly 3.785411784 litres.

Others are conventions. A cup is 236.5882365 ml because the US customary cup is defined that way — a metric cup of 250 ml exists and is used in Australia, and a UK cup is 284 ml. If a recipe came from a different country, the number can be right and the result still wrong.

Decimal and binary data units

The data category keeps both systems, because both are in daily use. KB, MB, GB and TB are powers of 1000 — that is what drive manufacturers and network engineers mean. KiB, MiB and GiB are powers of 1024 — that is what operating systems often display.

This is why a “500 GB” drive shows as about 465 GiB in a file manager. Neither figure is wrong; the units differ. Pick the column that matches the tool you are comparing against.

Rounding and precision

Results are shown to a sensible number of significant figures rather than a raw float, because 0.30000000000000004 mm helps nobody. For engineering work, take the factor from the definition above and do the arithmetic in your own tool at full precision.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions