Converters
Temperature Converter
Convert Celsius, Fahrenheit and Kelvin.
About the Temperature Converter
The Temperature Converter switches between Celsius, Fahrenheit and Kelvin as you type, showing all three at once with a thermometer bar. Tap reference points like body temperature, a hot day or an oven setting, and use the quick table for common values.
What you can do with the Temperature Converter
- All three at once: Celsius, Fahrenheit and Kelvin update together as you type.
- Thermometer bar: A coloured bar shows where the temperature sits, from freezing to boiling.
- Reference points: Tap body temperature, a hot day or an oven setting to fill it in.
- Quick table: Common values side by side for a fast look-up.
The formulas
Fahrenheit = Celsius × 9/5 + 32, and Celsius = (Fahrenheit − 32) × 5/9. Kelvin = Celsius + 273.15. A quick mental estimate from Celsius to Fahrenheit is "double it and add 30", close enough for everyday weather.
Useful reference points
Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F) at sea level. Normal body temperature is about 37 °C (98.6 °F). At −40 the Celsius and Fahrenheit scales meet, so −40 °C is exactly −40 °F. Ovens for baking are usually set around 180 °C (356 °F).
Kelvin and absolute zero
Kelvin starts at absolute zero, the coldest possible temperature: 0 K, −273.15 °C or −459.67 °F. Scientists use it because it has no negative values, and the converter warns you if a value would go below it. Kelvin is written without the degree sign, 300 K, not 300 °K.
Related tools
Frequently Asked Questions
What is 37 °C in Fahrenheit?
98.6 °F, typical human body temperature. Tap "Body 37°C" to see it.
Is there a temperature that's the same in Celsius and Fahrenheit?
Yes, −40. It's the only point where the two scales give the same number.
Can a temperature in Kelvin be negative?
No. 0 K is absolute zero, so Kelvin values are always zero or positive.
How do I convert a temperature change, not a temperature?
A change of 1 °C equals a change of 1.8 °F, so a rise of 10 °C is a rise of 18 °F, not 50 °F. The +32 offset applies only to actual temperatures. The tool converts temperatures, so multiply differences by 1.8 yourself.
What is 180 °C in Fahrenheit for an oven?
180 °C is 356 °F, and 200 °C is 392 °F. US recipes often round these to 350 °F and 400 °F. Tap the Oven reference point to fill in 180 °C, or check common values in the quick table.
What is 45 °C in Fahrenheit?
45 °C is 113 °F, a summer temperature reached in parts of north and central India. 40 °C is 104 °F and 50 °C is 122 °F. Type the value with °C selected and the thermometer bar shows it in the hot red range.
Is there a quick way to convert Celsius to Fahrenheit in my head?
Double the Celsius figure and add 30 for a rough answer. For 30 °C that gives 90 °F against the exact 86 °F. The exact rule is to multiply by 1.8, or 9/5, and add 32.
What is absolute zero in Celsius and Fahrenheit?
Absolute zero is 0 K, which is -273.15 °C or -459.67 °F, the lowest temperature possible. If you type a value below it in any scale, the tool shows a warning that the temperature cannot exist.
Why is Kelvin written without a degree sign?
Kelvin is an absolute scale, so its unit is simply the kelvin, written K, as in 300 K. Celsius and Fahrenheit use degrees. One kelvin step is the same size as one Celsius degree, so K equals °C plus 273.15.
What range does the thermometer bar show?
The bar runs from -30 °C to 130 °C and changes colour from blue below freezing through green and yellow to red from 40 °C upwards. Values outside that range still convert correctly; the bar simply stays empty or full.
How many decimal places does the result show?
Results are rounded to two decimal places, so 37 °C shows as 98.6 °F and 310.15 K. You can type decimals too, such as 36.6, and the other two scales update as you type.
Read the guide
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