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Temperature Converter
Conversion Calculator
Temperature Converter
Convert Fahrenheit, Celsius, and Kelvin instantly. Use it for ambient conditions, workshop planning, cooking references, material storage, or science calculations.
Convert temperature
Temperature conversion formulas
- Celsius = (Fahrenheit - 32) x 5 / 9
- Fahrenheit = Celsius x 9 / 5 + 32
- Kelvin = Celsius + 273.15
- Celsius = Kelvin - 273.15
Unlike length or area conversions, temperature scales do not all begin at the same zero point. Fahrenheit-to-Celsius conversion therefore requires both subtraction and multiplication, not a single scale factor.
Worked example: 72 F
Subtract 32 from 72 to get 40, then multiply by 5/9. The result is 22.22 C. Add 273.15 to the Celsius value to get approximately 295.37 K.
Useful reference temperatures
- Water freezes at 32 F, 0 C, or 273.15 K under standard reference conditions.
- Water boils at about 212 F, 100 C, or 373.15 K at standard atmospheric pressure.
- Absolute zero is -459.67 F, -273.15 C, or 0 K.
Actual boiling temperature changes with atmospheric pressure and elevation. Material cure times and product performance may also depend on surface temperature, humidity, airflow, and manufacturer instructions.
Accuracy and appropriate use
The formulas are mathematical conversions, but the accuracy of a real-world reading depends on the thermometer, its calibration, placement, and response time. This page is intended for general ambient, cooking, workshop, and science conversions. It is not medical advice and should not replace an appropriate clinical instrument or professional guidance.
Frequently asked questions
What is 20 C in Fahrenheit?
Multiply 20 by 9/5 and add 32. The result is 68 F.
When are Fahrenheit and Celsius equal?
The two scales have the same numerical value at -40: -40 F equals -40 C.
Does Kelvin use a degree symbol?
No. The SI unit is written as kelvin, symbol K, without the degree symbol.
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Sources and review
Scale definitions and SI conventions follow information from the National Institute of Standards and Technology. Calculator logic and examples were reviewed by the DIY Cost Tools editorial team on September 22, 2026.