Converting between Celsius and Kelvin

The Kelvin and Celsius scales differ only in the temperatures chosen as their zeros.

Celsius (°C)	−273	−100	0	100	200
Kelvin (K)	0	173	273	373	473

Figure 9.7 — the Celsius and Kelvin scales side by side.

Celsius to Kelvin

Add 273.

Kelvin to Celsius

Subtract 273.

Example 1

How many Kelvin divisions equal one Celsius division? Convert 50 °C to kelvin, and 373 K to degrees Celsius.

100 Celsius divisions = 100 Kelvin divisions, so 1 Celsius division = 1 Kelvin division

50 °C = 50 + 273 K = 323 K

373 K = 373 − 273 °C = 100 °C

Exercise 9.1

(1) 10 °C, 27 °C, 87 °C, 127 °C and 100 °C in kelvin. (2) 0 K, 100 K, 273 K, 373 K and 400 K in degrees Celsius.

The answer

(1) 283 K, 300 K, 360 K, 400 K, 373 K

(2) −273 °C, −173 °C, 0 °C, 100 °C, 127 °C