Unit Converters
Temperature Converter
Temperature: it converts between Celsius, Fahrenheit and Kelvin with affine formulas, so zero does not map to zero. Worked through below with real figures, and the calculator repeats the working on your own inputs — free, on-device, instant.
Temperature Converter lets you convert a temperature measurement between units such as Celsius, Fahrenheit and Kelvin in seconds: enter your value plus the source and target units for the converted temperature in the unit you choose, all worked out locally in your browser.
About this calculator
Temperature is easiest to get wrong in the setup, not the arithmetic. It converts between Celsius, Fahrenheit and Kelvin with affine formulas, so zero does not map to zero. It matters whenever the same quantity is expressed in two systems and a wrong factor silently breaks the answer. The worked example on this page (Convert 25°C to Fahrenheit: 25 × 9/5 + 32 = 77°F . The same 25°C is 298.15 K (add 273.15).) shows the full substitution; the calculator above runs the same working on your own numbers, in your browser, with nothing uploaded.
How to use
- Enter the temperature value.
- Choose the From scale.
- Choose the To scale.
- Press Calculate to see the converted temperature.
Why use Temperature Converter
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Accurate
Uses standard conversion factors where applicable. Check critical measurements before relying on the result.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Honest disclaimers wherever browser limits or regional rules apply.
Common uses
Use it for 3D-printing temperatures
Temperature in brewing and fermentation
Use it when comparing Celsius and Fahrenheit
Use it for a medical temperature check
Use it for HVAC and thermostat settings
Use it for cooking and oven settings
Technical notes
Temperature Converter converts between Celsius, Fahrenheit and Kelvin with affine formulas, so zero does not map to zero.
Conversions use standard reference factors; for trade or engineering tolerances keep more decimal places than the display shows.
Because it runs locally, results appear instantly with no server round-trip.
FAQ
Which scales are supported?
Celsius, Fahrenheit, Kelvin, and Rankine.
Can negative temperatures be converted?
Yes, down to absolute zero. Inputs below absolute zero for the chosen scale are rejected.
What is absolute zero on each scale?
0 K and 0 °R, which equal −273.15 °C and −459.67 °F.
Does the Temperature Converter send my data to a server?
No. The Temperature Converter runs entirely in your browser, so nothing you enter is uploaded, stored, or shared.
Worked example
Convert 25°C to Fahrenheit: 25 × 9/5 + 32 = 77°F. The same 25°C is 298.15 K (add 273.15).