Unit Converter — Length, Weight & More

Unit conversion is the task that turns a known number into a usable one. Sixty-nine inches is a height; 175.26 cm is the same height in a form a European tape measure can confirm. Unit Converter covers four measurement families — length, weight, volume and temperature — in one place, so a single tab handles the grocery scale, the fuel receipt and the fever thermometer without switching tools.

Every conversion runs entirely in the browser. Nothing is sent anywhere, which matters for the cases where the number being converted carries context: a patient weight, a drug dosage, a construction measurement with a tight tolerance.

How to Use It

1. Pick a domain tab: Length, Weight, Volume or Temperature.
2. Select the unit you are converting From in the left dropdown, then type your value.
3. Select the unit to convert To in the right dropdown. The result updates instantly.
4. Click the ⇄ Swap button to reverse direction; the result becomes the new input automatically.
5. Scroll down to the All Units reference table, which shows the same input converted into every unit in the domain at once. The active target row is highlighted in terracotta.

Conversion Method

Length, weight and volume all convert through a single base unit: metres, kilograms and litres respectively. Every unit stores its exact factor to that base, so any pair converts in two multiplications with no accumulated error. Temperature uses explicit formulas: °F = °C × 9/5 + 32, K = °C + 273.15, and °R = (°C + 273.15) × 9/5. The Rankine scale is included because engineering datasheets and older US standards still use it — 98.6 °F is 37 °C is 310.15 K is 558.27 °R.

Precision and Coverage

• Results are shown to up to 10 significant figures with trailing zeros removed. 1 US gallon = 3.78541 L exactly by the 1959 international yard and pound agreement.
• Length covers 9 units from millimetres to nautical miles. Weight covers 8 units from milligrams to short tons. Volume covers 12 units from millilitres to cubic feet.
• Switching domains resets the unit selectors to the first pair in that family; the input value is also cleared to avoid a silent domain mismatch.
• The Swap button transfers the numeric result into the input field. If the result is not a finite number (empty input, non-numeric entry), the swap still flips the selectors without touching the input.