Thermodynamics · Quick Reference

Temperature Cheat Sheet

Thermodynamics · Lesson 1/10

In one line: temperature measures how hot or cold something is by quantifying the average kinetic energy of its particles — a concept so fundamental it needed its own dedicated scales and instruments.

Key Ideas

1What Temperature Measures. The average kinetic energy of the particles in a substance -- higher temperature means faster-moving particles on average.

2Common Temperature Scales. Celsius (°C, water freezes at 0, boils at 100), Fahrenheit (°F, water freezes at 32, boils at 212), and Kelvin (K, the absolute scale, starting at absolute zero).

3Absolute Zero. 0 Kelvin (-273.15°C), the theoretical temperature at which particle motion is at its minimum possible energy -- it can never actually be fully reached.

4Converting Between Scales. K = °C + 273.15. °F = (°C x 9/5) + 32. °C = (°F - 32) x 5/9.

5Thermal Equilibrium. The state reached when two objects in contact stop exchanging net heat because they've reached the same temperature.

Worked Examples

Convert 25°C to Kelvin.

298.15 K

Convert 100°C to Fahrenheit.

212°F

Convert 68°F to Celsius.

20°C

Formulas

K = °C + 273.15

°F = (°C * 9/5) + 32

°C = (°F - 32) * 5/9

Practice Yourself

Convert 0°C to Kelvin.

273.15 K

Convert 37°C (body temp) to Fahrenheit.

98.6°F

Convert 32°F to Celsius.

0°C