🌡️ Fahrenheit to Kelvin Converter
Instantly convert temperatures from Fahrenheit (°F) to Kelvin (K). The Kelvin scale is the SI base unit of temperature, used in science and engineering, with 0 K equal to absolute zero (−459.67 °F).
What Is the Kelvin Scale?
The Kelvin scale (K) is the SI base unit of temperature, named after the British physicist Lord Kelvin (William Thomson) (1824–1907). It is an absolute thermodynamic temperature scale, meaning it starts at absolute zero, the point where all molecular motion ceases.
Key characteristics of the Kelvin scale:
- Zero point: 0 K is absolute zero, equivalent to −273.15 °C or −459.67 °F.
- Degree size: A Kelvin is the same size as a degree Celsius (1 K = 1 °C), not a degree Fahrenheit (1 K = 1.8 °F).
- Freezing point of water: 273.15 K (0 °C, 32 °F).
- Boiling point of water: 373.15 K (100 °C, 212 °F).
- Conversion to Fahrenheit: K = (°F − 32) × 5/9 + 273.15.
The Kelvin scale is widely used in science, engineering, and thermodynamics, especially in fields like physics, chemistry, and astronomy.
How to Convert Fahrenheit to Kelvin
The formula to convert Fahrenheit to Kelvin is:
K = (°F − 32) × 5/9 + 273.15
Alternatively: K = (°F + 459.67) × 5/9
This formula works because:
- Subtracting 32 converts Fahrenheit to a zero‑based scale relative to the freezing point of water.
- Multiplying by 5/9 converts the Fahrenheit degree size to the Celsius/Kelvin degree size.
- Adding 273.15 shifts the scale to absolute zero.
For example, to convert 212 °F (the boiling point of water) to Kelvin:
K = (212 − 32) × 5/9 + 273.15
K = 180 × 5/9 + 273.15
K = 100 + 273.15
K = 373.15 K
Why Use This Converter?
- Instant results: Get accurate conversions in real-time.
- Step-by-step breakdown: See exactly how the conversion is calculated.
- Common reference table: Quickly check temperatures from −40 °F to 200 °F.
- Free & private: No registration, no data storage — all calculations are done in your browser.
❓ Fahrenheit to Kelvin FAQ
What is the formula to convert Fahrenheit to Kelvin?
The formula is K = (°F − 32) × 5/9 + 273.15. Alternatively, you can use K = (°F + 459.67) × 5/9.
What is the Kelvin scale used for?
The Kelvin scale is the SI base unit of temperature and is widely used in science, engineering, and thermodynamics. It is used in physics, chemistry, astronomy, and many other scientific fields.
What is the difference between Kelvin and Celsius?
Both scales have the same degree size (1 K = 1 °C), but they have different zero points. 0 K is absolute zero (−273.15 °C), while 0 °C is the freezing point of water (273.15 K).
What is absolute zero in Kelvin?
Absolute zero is 0 K, which is equivalent to −273.15 °C and −459.67 °F.
What is the freezing point of water in Kelvin?
Water freezes at 273.15 K (0 °C, 32 °F).
What is the boiling point of water in Kelvin?
Water boils at 373.15 K (100 °C, 212 °F).
Who invented the Kelvin scale?
The Kelvin scale was invented by Lord Kelvin (William Thomson) (1824–1907), a British physicist and engineer.
Is Kelvin still used today?
Yes, the Kelvin scale is the standard unit of temperature in the SI system and is used extensively in science and engineering worldwide.
How accurate is this converter?
This converter provides highly accurate results using the standard conversion formula K = (°F − 32) × 5/9 + 273.15. You can adjust the decimal precision to suit your needs.
Is this converter free?
Yes, this converter is completely free to use. No registration or personal data storage is required.