Convert Celsius to Fahrenheit and back, with Kelvin shown alongside and a quick reference table.
Type into either box and the other updates as you go. Kelvin is shown too, along with a table of the temperatures people look up most.
Conversion
20 °C = 68 °F
293.15 KKelvin
Room temperatureFeels like
How Does It Work?
Type in either boxCelsius on the left, Fahrenheit on the right. Whichever you edit, the other follows.
Read the conversionThe formula is written out underneath so you can see exactly how the number was reached.
Check the reference tableBody temperature, oven settings and weather ranges are listed below for quick lookups.
What Is It Used For?
Two countries and one scale apart: recipes, weather forecasts, medical thermometers and oven dials all switch between Celsius and Fahrenheit depending on where they were written. The conversion is not a simple multiplication because the two scales have different zero points as well as different step sizes.
Following a recipe with oven temperatures in the other scale.
Reading a weather forecast from abroad.
Checking whether a fever reading is high, in either scale.
Setting an air conditioner or thermostat sold in another market.
Homework and science problems that mix scales.
Examples
Celsius
Fahrenheit
What it is
−40 °C
−40 °F
The point where both scales meet
0 °C
32 °F
Water freezes
20 °C
68 °F
Comfortable room temperature
37 °C
98.6 °F
Normal body temperature
100 °C
212 °F
Water boils at sea level
180 °C
356 °F
Common baking temperature
Frequently Asked Questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 (that is 1.8) and add 32. So 20 °C × 1.8 = 36, plus 32 = 68 °F.
How do I convert Fahrenheit to Celsius?
Subtract 32 first, then multiply by 5/9. So 68 °F − 32 = 36, times 0.5556 = 20 °C.
Is there a quick mental shortcut?
Double the Celsius value and add 30 for a rough Fahrenheit figure. 20 °C gives about 70 °F, close to the exact 68 °F. Going the other way, subtract 30 and halve.
At what temperature are Celsius and Fahrenheit the same?
At −40 degrees. It is the only point where the two scales give the same number.
What is normal body temperature?
Around 37 °C or 98.6 °F, though healthy readings range from roughly 36.1 °C to 37.2 °C (97 °F to 99 °F) depending on the person, the time of day and where it is measured.
How does Kelvin relate to Celsius?
Kelvin uses the same step size as Celsius but starts at absolute zero, so K = °C + 273.15. Water freezes at 273.15 K.
What are the common oven temperatures?
160 °C is 320 °F, 180 °C is 356 °F and 200 °C is 392 °F. Recipes round these to the nearest dial marking — usually 325 °F, 350 °F and 400 °F — because a few degrees either way makes no practical difference to baking.
Why does the weather feel different in each scale?
Because a Fahrenheit degree is smaller: 1.8 of them fit inside one Celsius degree. Fahrenheit numbers therefore move faster and spread everyday weather across a range of roughly 0 to 100, which is part of why it feels intuitive to those raised with it.
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