Celsius, Fahrenheit, Kelvin & Rankine Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin, and Rankine temperature scales.
Output will appear here
Click in the output to select all text
Related tools
Comprehensive Multi-Unit Converter
Convert across 10+ categories: Length, Weight, Temperature, Area, Volume, Speed, Energy, Pressure, Power, and Data Storage.
Length Unit Converter
Convert between metric and imperial length units (mm, cm, m, km, in, ft, yd, mi).
Weight Unit Converter
Convert between metric and imperial weight units (mg, g, kg, oz, lb, metric ton, US ton).
Pressure Unit Converter
Convert between Pascal (Pa), Bar, PSI, Standard Atmosphere (atm), and Torr.
Energy & Work Unit Converter
Convert between Joules, Kilojoules, Calories, Kilocalories (kcal), kWh, and BTU.
This temperature converter switches between Celsius, Fahrenheit, Kelvin, and Rankine in real time, so you never have to remember the formulas yourself. It's useful for students learning thermodynamics, home cooks following a recipe written in the other scale, travelers checking foreign weather forecasts, and scientists who need Kelvin or Rankine for lab work. Just enter a value in any one of the four scales and the other three update immediately, calculated with the standard conversion formulas used in science and everyday life. There's nothing to install and nothing to sign up for — the calculator is free to use as many times as you like. Since the conversion math runs entirely in your browser, none of your inputs are ever transmitted or stored on a server, making it a quick, private way to double-check a temperature reading. Scroll down to enter your value and see every scale update instantly.
Features
- Converts between Celsius, Fahrenheit, Kelvin, and Rankine simultaneously
- Live, instant updates as you type a value in any field
- Uses standard scientific conversion formulas
- Handles negative temperatures and decimals correctly
- Simple single-screen layout, no extra clicks needed
- Works on any device with a browser
Why use this temperature unit converter?
- Instant conversion with no delay or page reload
- Private — calculations happen locally, nothing is uploaded
- Formula-accurate results down to the decimal
- Easy enough for students, useful enough for scientists
- Completely free with unlimited use
Frequently asked questions
What is the formula to convert Celsius to Fahrenheit?
Fahrenheit = (Celsius × 9/5) + 32. This calculator applies that formula automatically as you type.
What is 0 degrees Celsius in Kelvin?
0°C equals 273.15 Kelvin, since the Kelvin scale starts at absolute zero (-273.15°C).
What is Rankine used for?
Rankine is an absolute temperature scale used mainly in older engineering and thermodynamics calculations in the US, analogous to Kelvin but based on Fahrenheit degrees.
How do I convert Fahrenheit to Celsius?
Celsius = (Fahrenheit − 32) × 5/9. Enter the Fahrenheit value and the tool calculates this for you instantly.
Is this temperature converter accurate for scientific work?
Yes, it uses the exact standard conversion formulas, though for high-precision lab work always confirm with your instrument's calibration.
Can I convert negative temperatures?
Yes, the calculator correctly handles negative values across all four temperature scales.