How do I convert Celsius to Fahrenheit?

Multiply by 9/5 (or 1.8) and add 32. For 25 °C: 25 × 1.8 + 32 = 77 °F.

How do I convert Fahrenheit to Celsius?

Subtract 32, then multiply by 5/9. For 77 °F: (77 − 32) × 5/9 = 25 °C.

What is 0 Kelvin in Celsius?

0 K is absolute zero, −273.15 °C.

At what temperature are Celsius and Fahrenheit equal?

At −40. Set °C = °F in the formula and solve.

Temperature Converter

Convert between Celsius, Fahrenheit and Kelvin.

Updated September 19, 2026Checked by the editorial team

Value

From

Celsius to Fahrenheit

33.8 °F

1 °C = 33.8 °F

Decimal places

Show 1 °C in every unit

Unit	Value
Fahrenheit	33.8 °F
Kelvin	274.15 K

Enter a temperature and choose the scale you have and the scale you want. Celsius, Fahrenheit and Kelvin are supported, and the result updates as you type.

Temperature scales have different zero points as well as different step sizes, so they cannot be converted by multiplying alone. That is why the formulas below have an addition or subtraction in them.

How temperature converter works

The tool converts the input to Celsius first, then to the target scale. Celsius and Kelvin have the same step size, so K = °C + 273.15. Fahrenheit degrees are smaller: 100 Celsius degrees span the same range as 180 Fahrenheit degrees, and the scale starts 32 degrees higher.

The formula

°F  =  °C × 9/5 + 32
°C  =  (°F − 32) × 5/9
K  =  °C + 273.15

The two scales meet at −40, where −40 °C equals −40 °F.

Worked example: body, oven and room

Normal body temperature, 37 °C: 37 × 9/5 + 32 = 98.6 °F.

An oven at 350 °F: (350 − 32) × 5/9 = 176.7 °C. Recipes usually round this to 175 or 180 °C.

A room at 20 °C is 68 °F, and 300 K is 26.85 °C.

Reference points

Celsius	Fahrenheit	What it is
−40 °C	−40 °F	The scales meet
0 °C	32 °F	Water freezes
20 °C	68 °F	Room temperature
37 °C	98.6 °F	Typical body temperature
100 °C	212 °F	Water boils at sea level
180 °C	356 °F	Common oven setting

When to use this converter

Reading weather forecasts and thermostats from another country.
Converting oven settings in recipes.
School and lab work that mixes Celsius and Kelvin.
Checking fever readings on foreign thermometers.

Common mistakes to avoid

Multiplying by 9/5 and forgetting to add 32 (or subtracting 32 after multiplying instead of before).
Using the rough shortcut “double it and add 30” for precise work. It is only a mental estimate for everyday weather.
Writing degrees with Kelvin. Kelvin is written K, without a degree sign.

Frequently asked questions

How do I convert Celsius to Fahrenheit?: Multiply by 9/5 (or 1.8) and add 32. For 25 °C: 25 × 1.8 + 32 = 77 °F.
How do I convert Fahrenheit to Celsius?: Subtract 32, then multiply by 5/9. For 77 °F: (77 − 32) × 5/9 = 25 °C.
What is 0 Kelvin in Celsius?: 0 K is absolute zero, −273.15 °C.
At what temperature are Celsius and Fahrenheit equal?: At −40. Set °C = °F in the formula and solve.

Learn more

Results are for information only and are not financial, legal or medical advice. The calculation logic is covered by automated tests, and examples on this page are worked out and re-checked before publishing. Spotted a mistake? Tell us.