Temperature Unit Conversion: Celsius, Fahrenheit, Kelvin Conversion Guide
Whether you're performing scientific calculations, processing weather data, or cooking in the kitchen, temperature conversion is a common requirement. This guide will provide you with detailed information about the most commonly used temperature units—Celsius (°C), Fahrenheit (°F), Kelvin (K), and Rankine (R)—as well as unit conversion methods between them. Using our online tools, you can quickly complete Celsius and Kelvin conversion, Celsius and Fahrenheit conversion, and any other temperature unit conversions.
Temperature Unit Definitions and Conversion Formulas
To accurately perform temperature conversion, it's essential to first understand the definitions of each unit. The table below clearly shows the definitions and core conversion formulas for Celsius, Kelvin, Fahrenheit, and Rankine.
| Unit Symbol | English Name | Unit Name | Definition | Conversion Formulas |
|---|---|---|---|---|
| °C | Celsius | Celsius | At standard atmospheric pressure, pure water freezes at 0°C and boils at 100°C. The Celsius symbol is °C. | - → K: ( K = °C + 273.15 ) - → °F: ( °F = °C × 1.8 + 32 ) - → R: ( R = (°C + 273.15) * 1.8 ) |
| K | Kelvin | Kelvin | Thermodynamic temperature scale, absolute zero = 0K. Kelvin and Celsius conversion is very simple and is the preferred choice in scientific research. | - → °C: ( °C = K - 273.15 ) - → °F: ( °F = (K - 273.15) × 1.8 + 32 ) - → R: ( R = K * 1.8 ) |
| °F | Fahrenheit | Fahrenheit | At standard atmospheric pressure, pure water freezes at 32°F and boils at 212°F. Commonly used in the United States. | - → °C: ( °C = (°F - 32) ÷ 1.8 ) - → K: ( K = (°F - 32) ÷ 1.8 + 273.15 ) - → R: ( R = °F + 459.67 ) |
| R | Rankine | Rankine | Absolute temperature scale in imperial units, absolute zero = 0R. Mainly used in engineering fields. | - → °F: ( °F = R - 459.67 ) - → K: ( K = R / 1.8 ) - → °C: ( °C = (R / 1.8) - 273.15 ) |
Common Temperature Conversion Details
Celsius to Kelvin Conversion (C to K)
Celsius and Kelvin conversion is one of the most common conversions in scientific calculations. Since they have the same temperature scale intervals, the conversion is very straightforward.
- From Celsius to Kelvin:
K = °C + 273.15 - From Kelvin to Celsius:
°C = K - 273.15
Celsius to Fahrenheit Conversion (C to F)
This is the most common temperature conversion in daily life, especially between different countries.
- From Celsius to Fahrenheit:
°F = °C × 1.8 + 32 - From Fahrenheit to Celsius:
°C = (°F - 32) ÷ 1.8
What is Absolute Zero?
Absolute zero is the theoretical lower limit of temperature, where the kinetic energy of matter's molecules is zero. In the Kelvin (K) and Rankine (R) temperature scales, 0 degrees represents absolute zero.
0 K = -273.15 °C0 R = -459.67 °F
Daily Applications of Temperature Units
- Celsius (°C): The standard unit used by the vast majority of countries worldwide and in scientific fields.
- Fahrenheit (°F): Mainly used in the United States and its territories, commonly seen in weather forecasts and daily body temperature measurements.
- Kelvin (K): The base unit of the International System of Units (SI), widely used in physics, chemistry, and other scientific research.
- Rankine (R): Mainly used in specific engineering fields (such as thermodynamics), very rare in daily life.