Last updated: April 2026
The Temperature Converter lets you switch between Celsius, Fahrenheit, and Kelvin in a single click. Select your input unit, type a temperature, and see both other scales calculated instantly. Whether you are converting a recipe from a European cookbook (Celsius to Fahrenheit for your oven), checking weather forecasts from different countries, or doing science homework that requires Kelvin, this tool gives you accurate results right away. A handy reference table shows common temperatures like water freezing, body temperature, water boiling, and absolute zero so you always have context for your conversions. The tool handles negative temperatures, decimal values, and all edge cases. Everything runs in your browser.
Click Celsius, Fahrenheit, or Kelvin to choose which temperature scale you are starting with. The tool adjusts the conversion formulas automatically.
Type the temperature you want to convert. The tool accepts whole numbers, decimals, and negative values. Results appear instantly as you type.
Both other temperature scales are displayed in highlighted cards below your input. You see all three values side by side for easy comparison.
Click Copy Results to grab a formatted string showing the full conversion. Use the Common Temperatures table below for quick reference points.
Temperature Converter is the fastest way to convert temperatures online. Key advantages include three-scale conversion, a reference table, and accurate handling of all temperature values.
Multiply the Celsius temperature by 9/5 (or 1.8) and then add 32. The formula is F = (C x 9/5) + 32. For example, 100 degrees Celsius equals (100 x 1.8) + 32 = 212 degrees Fahrenheit. A quick mental shortcut: double the Celsius value and add 30 for a rough Fahrenheit estimate.
Subtract 32 from the Fahrenheit temperature and then multiply by 5/9. The formula is C = (F - 32) x 5/9. For example, 72 degrees Fahrenheit equals (72 - 32) x 5/9 = 22.2 degrees Celsius. A quick estimate: subtract 30 and divide by 2.
Kelvin is the standard unit of temperature in science and engineering. It starts at absolute zero (0K = -273.15 degrees Celsius), which is the lowest possible temperature where all molecular motion stops. Kelvin is used in physics, chemistry, astronomy, and any scientific context where an absolute temperature scale is needed. It uses the same degree size as Celsius.
The two scales intersect at -40 degrees. At -40 degrees Celsius, the temperature is also -40 degrees Fahrenheit. You can verify this with the formula: (-40 x 9/5) + 32 = -72 + 32 = -40. This is one of the most commonly asked temperature trivia questions.
The Fahrenheit scale was created in 1724 by Daniel Gabriel Fahrenheit and was widely adopted in English-speaking countries. Most of the world switched to Celsius (also called Centigrade) during the metrication movement in the 1960s and 1970s. The United States, along with a few other countries, kept Fahrenheit for everyday use, though Celsius and Kelvin are used in US science and medicine.