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Temperature scales
Beginner
Celsius, Kelvin and Fahrenheit.
Key relation
K = °C + 273.15Celsius sets 0 and 100 at water's freezing and boiling points; Kelvin starts at absolute zero, K = °C + 273.15; Fahrenheit F = 1.8C + 32. Physics formulas need kelvin.
Worked example
300 K = 26.85 °C = 80.3 °F.
Common mistake
A change of 1 K equals a change of 1 °C.
In more detail
Common scales include Celsius, Fahrenheit and Kelvin. The Kelvin scale starts at absolute zero, and one kelvin equals one degree Celsius in size.
Real-world uses
- Scientific work uses kelvin, while weather reports often use Celsius.
- Fahrenheit is still common in some countries for everyday temperatures.
- Scientific papers use kelvin, while everyday weather uses degrees Celsius, so conversions are needed when comparing results.
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Frequently asked questions
How do I convert Celsius to Kelvin?
Add 273.15 to the Celsius temperature.
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32.
Why is zero kelvin the lowest possible temperature?
It is absolute zero, where the particles have their minimum possible energy, so no lower temperature can be reached.