FlowToolkit
Utility

Unit Converter

Convert length, mass, temperature, volume, and more.

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About this tool

A fast unit converter for everyday and engineering use. Supports length, mass, temperature, time, volume, and data units. Conversions are computed instantly as you type.

Why an in-browser unit converter?

Every engineer, scientist, designer, cook, and traveller eventually needs to convert between metric and imperial, or between SI base units and their derived forms. A search engine usually answers the question but with two costs: it sends your query to a remote server, and it gives you exactly one conversion at a time. A dedicated tool lets you bookmark, run conversions side by side, copy results in bulk, and trust that nothing about your input is logged.

Supported categories

  • Length — millimetre, centimetre, metre, kilometre, inch, foot, yard, mile, nautical mile.
  • Mass — milligram, gram, kilogram, tonne, ounce, pound, stone.
  • Temperature — Celsius, Fahrenheit, Kelvin, Rankine.
  • Time — millisecond, second, minute, hour, day, week, month, year.
  • Volume — millilitre, litre, cubic metre, US gallon, imperial gallon, fluid ounce.
  • Data — bit, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte (binary IEC and decimal SI both supported).

Precision and accuracy

Results are computed using IEEE-754 double-precision floating point — the same arithmetic engine used by scientific calculators, spreadsheets, and most programming languages. Output is rounded to six significant figures by default, which is comfortably above the precision required for most engineering and household tasks. For applications requiring exact rational arithmetic, the underlying values are exposed in the source code for verification.

Frequently asked questions

Which categories are supported?

Length, mass, temperature, time, volume, and data. Each category includes both metric and imperial units.

Is precision configurable?

Results round to 6 significant figures by default, which is sufficient for most everyday and engineering tasks.

How many meters are in a mile?

1 mile equals 1,609.344 meters exactly. Use the length converter for any combination of metric and imperial length units.

How do I convert Celsius to Fahrenheit?

Switch to the temperature category, choose Celsius as the source unit and Fahrenheit as the target, and type the value. The formula is (C × 9/5) + 32.

How do I convert kilograms to pounds?

Switch to the mass category, choose kilogram as the source and pound as the target. One kilogram equals approximately 2.20462 pounds.

What units of data are supported?

Bit, byte, kilobyte, megabyte, gigabyte, terabyte, and petabyte. Both binary (IEC kibibyte, mebibyte) and decimal (SI kilobyte, megabyte) interpretations are available.

Does the converter work offline?

Once the page has loaded, yes. All conversions are computed locally in your browser using JavaScript.