Unit Converter Online Free — Length, Weight, Temperature & More

How unit conversion works here

Factor-based conversion

For most categories each unit gets a fixed factor relative to a base unit (metres for length, grams for mass, seconds for time, and so on). Converting from unit A to unit B multiplies by B's factor and divides by A's — the same arithmetic a spreadsheet would do, with the full-precision factors kept internally and only the result rounded for display.

Temperature is the exception: Celsius, Fahrenheit, and Kelvin have offsets as well as scale differences, so the tool applies the exact formulas instead of a single factor (for example °F = °C × 9/5 + 32, K = °C + 273.15).

Metric vs imperial quick reference

Decimal or binary data units?

This tool uses the decimal convention: 1 KB = 1,000 bytes, 1 MB = 1,000 KB, and so on — the same one hard-drive and SSD makers use. Operating systems often report sizes in binary units (1 KiB = 1,024 bytes), which is why a "1 TB" drive shows about 909 GB in Windows or macOS.

If your numbers disagree with your OS by a few percent, that convention difference — not a rounding error — is almost always why.