Translate scales with different zero points
Temperature conversion differs from most unit conversion because Celsius, Fahrenheit, and Kelvin do not share the same zero point. A temperature must be shifted as well as scaled. That is why doubling a Celsius reading does not double its Fahrenheit equivalent.
Use this page for actual temperature readings such as weather, oven settings, refrigeration, laboratory conditions, and device specifications. Temperature intervals are a related but different idea: a change of 1°C equals a change of 1 K, while a change of 1°C equals a change of 1.8°F.
Celsius, Fahrenheit, and Kelvin formulas
FigureNest converts the source reading to Celsius as a common reference, then applies the destination scale equation.
Celsius to Fahrenheit: °F = (°C × 9/5) + 32.
Fahrenheit to Celsius: °C = (°F − 32) × 5/9.
Celsius to Kelvin: K = °C + 273.15.
Kelvin to Celsius: °C = K − 273.15.
Kelvin has no degree symbol; 0 K is absolute zero.
Conversions in real situations
Convert 68°F to Celsius.
68°F = 20°CSubtract 32 from 68 and multiply the remainder by 5/9.
Convert 180°C to Fahrenheit.
180°C = 356°FMultiply 180 by 9/5 and add 32. Real ovens may use rounded dial settings and cycle around the target.
Convert 25°C to Kelvin.
25°C = 298.15 KAdd 273.15. Celsius and Kelvin increments are the same size but start at different zero points.
Read the result in context
Weather apps may round to a whole degree, while scientific measurements can require decimal precision and calibrated sensors. Converting a rounded source does not restore information that was not measured.
Cooking conversions translate the stated temperature but cannot account for oven calibration, fan-assisted settings, rack position, cookware, or altitude. Follow safety guidance and check food doneness independently.
What this conversion does not decide
- Values below absolute zero are physically impossible and are rejected.
- The calculator converts temperature readings, not heat energy or temperature intervals.
- Sensor accuracy, calibration, and source rounding are outside the calculation.
- Cooking equipment may require its own conventional rounded setting.
- A converted threshold should not be given more precision than its source. A weather observation reported to the nearest whole degree remains approximate after conversion, even when the formula produces decimal places.
Temperature questions
What is the formula for Celsius to Fahrenheit?
Multiply the Celsius temperature by 9/5, then add 32.
At what temperature are Celsius and Fahrenheit equal?
The two scales show the same numerical value at −40: −40°C equals −40°F.
Why does Kelvin not use a degree symbol?
Kelvin is an absolute thermodynamic scale. Its unit name and symbol are kelvin and K, without the word degree or a degree symbol.
What is absolute zero on each scale?
Absolute zero is 0 K, −273.15°C, or −459.67°F.
Can I use the result as an exact oven setting?
Use it as a temperature conversion, then choose the nearest available oven setting and account for fan-assisted guidance and the appliance’s calibration.