Temperature Formula
Temperature measures the average kinetic energy of a substance’s particles (atoms and molecules). In simply terms, it indicates how hot or cold an object or environment is. Temperature is measured on a variety of scales, the most generally used being the Celsius (°C) scale. Other units include Fahrenheit and Kelvin. Temperature formula deals with conversion between one unit to other units. Learn more about temperaure formula and how to use them in this article by Extramarks.
Unit of Temperature
Temperature can be measured using various units, depending on the scale being used. The three most commonly used temperature scales and their units are:
- Celsius
- Fahrenheit
- Kelvin
Let’s learn them in detail below:
Celsius
Celsius (symbol: °C) is a unit of measurement for temperature widely used in everyday life and scientific contexts. It is named after the Swedish astronomer Anders Celsius, who proposed the Celsius temperature scale in 1742. The Celsius scale is based on dividing the temperature range between the freezing and boiling points of water into 100 equal intervals.
- The Celsius scale is extensively used in routine temperature measurement.
- On this scale, water’s freezing point is 0°C and its boiling point is 100°C, both at standard atmospheric pressure.
- The Celsius scale divides the temperature range between water’s freezing and boiling temperatures into 100 equal intervals.
- A typical room temperature could be around 20°C.
Fahrenheit
Fahrenheit, often abbreviated as °F, is another commonly used unit of measurement for temperature, particularly in the United States and a few other countries.
The Fahrenheit scale was developed by German physicist Daniel Gabriel Fahrenheit in the early 18th century.
- On this scale, the freezing point of water is defined as 32°F, and the boiling point of water is defined as 212°F, both at standard atmospheric pressure.
- The Fahrenheit scale is based on historical mercury-in-glass thermometer measurements.
- Example: A warm summer day might have a temperature of around 80°F.
Kelvin
Kelvin, often abbreviated as K, is the primary unit of measurement for temperature in the International System of Units (SI) and is widely used in scientific contexts, particularly in physics and chemistry.
The Kelvin scale is based on the properties of matter and is defined relative to absolute zero, the theoretical lowest possible temperature at which particles have minimal kinetic energy.
- On this scale, the lowest possible temperature, absolute zero (the point at which particles have minimal kinetic energy), is defined as 0 Kelvin.
- The Kelvin scale is based on the same size units as the Celsius scale, with 0 K being equivalent to -273.15°C.
- Example: Absolute zero is 0 K, and room temperature is approximately 298 K.
Temperature Conversion Formula
To convert temperatures between different temperature scales (Celsius, Fahrenheit, and Kelvin), you can use conversion formulas specific to each scale. Here are the temperature conversion formulas:
Temperature Conversion Formula between Celsius and Fahrenheit
The formula for temperature conversion between celsius and fahrenheit are mentioned below:
Celsius to Fahrenheit
F = (9/5) x C + 32
where,
- F is temperature in Fahrenheit
- C is temperature in Celsius
Fahrenheit to Celsius
C = (5/9) x (F – 32)
where,
- F is temperature in Fahrenheit
- C is temperature in Celsius
Temperature Conversion Formula between Celsius and Kelvin
The formula for temperature conversion between celsius and kelvin are mentioned below:
Celsius to Kelvin
K = C + 273.15
where,
- K is temperature in Kelvin
- C is temperature in Celsius
Kelvin to Celsius
C = K – 273.15
where,
- K is temperature in Kelvin
- C is temperature in Celsius
Temperature Conversion Formula between Fahrenheit and Kelvin
The formula for temperature conversion between fahrenheit and Kelvin are mentioned below:
Fahrenheit to Kelvin
K = (5/9) x (F – 32) + 273.15
Where,
- K is kelvin
- F is Fahrenheit
Kelvin to Fahrenheit
F = 9/5 ×(K−273.15)+32
Where,
- K is kelvin
- F is Fahrenheit
Temperature Conversion Table
Based on the above forrmulas, a temeperature conversion table conatining equivalent temperature in different is given below
| Celsius(ºC) |
Kelvin(K) |
Fahrenheit(ºF) |
| 0ºC |
273.15 K |
32ºF |
| 1ºC |
274.15 K |
33.8ºF |
| 2ºC |
275.15 K |
35.6ºF |
| 3ºC |
276.15 K |
37.4ºF |
| 4ºC |
277.15 K |
39.2ºF |
| 5ºC |
278.15 K |
41.0ºF |
| 10ºC |
283.15 K |
50ºF |
| 15ºC |
288.15 K |
59ºF |
| 20ºC |
293.15 K |
68ºF |
Solved Examples Using Temperature Formula
Example 1: Convert 20 degrees Celsius to Fahrenheit.
Solution:
The formula to convert Celsius to Fahrenheit is:
F=(C×9/5)+32
Given C=20 degrees Celsius
.F=(20×9/5)+32
F=(20×1.8)+32
F=36+32 = 68ºF
Example 2: Convert 300 Kelvin to Fahrenheit.
Solution:
To convert from Kelvin to Fahrenheit, you can use the following formula:
F = 9/5 ×(K−273.15)+32
Put Kelvin = 300
F = 9/5 ×(300−273.15)+32
F = 1.8 x 26.85 + 32 = 80.33ºF
Example 3: Convert 400 Kelvin to Celsius.
Solution:
To convert from Kelvin to Celsius, you can use the following formula:
C = 400 – 273.15 = 126.85ºC