Blog
Unit converters

Temperature converter

Enter a value, choose a source and target unit, and the converter recalculates temperature between any pair of four scales: Celsius, Fahrenheit, Kelvin and Rankine, correctly handling each scale's different reference point.

Your data never leaves this device

Result

Result

This page has no server side at all. The table you paste is parsed by JavaScript inside your own browser, the chart is drawn on a canvas element on your machine, and the export file is assembled locally. Nothing is uploaded, stored or written to any log. You can disconnect from the network after the page has loaded and everything will still work — which is the simplest way to verify the claim yourself.

Facts and limits of this method

Celsius → Fahrenheit formula F = C × 9/5 + 32
Celsius → Kelvin formula K = C + 273.15
Celsius → Rankine formula °R = (C + 273.15) × 9/5
Absolute zero 0 K = −273.15 °C = −459.67 °F = 0 °R

When it misleads you

How it is calculated

The entered value is first converted to degrees Celsius — for example, from Fahrenheit using C = (F − 32) × 5/9, from Kelvin using C = K − 273.15.

If the "from" unit is already Celsius, this step leaves the number unchanged.

The Celsius value is then converted to the target unit using the inverse formula — for example, to Fahrenheit using F = C × 9/5 + 32.

The result is rounded to the chosen number of decimal places and updates instantly whenever the value, units or precision change.

Questions and answers

Why can't I just multiply the temperature by a factor, like with length or mass?

Because the Celsius, Fahrenheit and Kelvin scales have different zero points — for example, 0 °C corresponds to 32 °F, not 0 °F, so an offset formula is needed instead of a single multiplication.

What is the Rankine scale?

An absolute temperature scale with a degree the same size as a Fahrenheit degree, but with zero at absolute zero — used mainly in US engineering calculations.

Can the result be below absolute zero?

Mathematically the converter doesn't prevent it, but such a result has no physical meaning — absolute zero (0 K = −273.15 °C) is the lower bound of possible temperature.

Is my data sent anywhere?

No, the whole calculation runs in your browser.

Related tools

All tools