Temperature Converter — Convert °C, °F & Kelvin Free Online
Convert between Celsius, Fahrenheit, and Kelvin
Instantly convert temperatures between Celsius, Fahrenheit, and Kelvin. Enter any value and see all conversions simultaneously.
Celsius
°C
Fahrenheit
°F
Kelvin
K
Visual Scale (−20°C to 120°C)
Reference Points
About Temperature Converter
Temperature is measured in three scales depending on context: Celsius (°C), used in most countries for everyday weather and science; Fahrenheit (°F), used in the United States for everyday temperatures; and Kelvin (K), used in science and engineering as the thermodynamic temperature scale.
Converting between these scales is a routine need for travellers encountering unfamiliar weather forecasts, cooks following recipes from different countries, scientists working with international publications, engineers designing systems that operate across temperature ranges, and anyone reading technical specifications from a different measurement tradition.
This converter accepts input in any of the three scales and instantly displays all three equivalents. Editing any field recalculates the other two, making it easy to explore the relationships between scales. Reference points are displayed for context: water freezes at 0°C / 32°F / 273.15 K and boils at 100°C / 212°F / 373.15 K at standard atmospheric pressure. Human body temperature is 37°C / 98.6°F / 310.15 K.
The Kelvin scale is particularly important in astrophysics (stellar temperatures reach millions of Kelvin), cryogenics, thermodynamics, and semiconductor physics. Understanding that Kelvin simply offsets Celsius by 273.15 makes conversions intuitive. All calculations are performed in your browser with no server interaction required.
Frequently Asked Questions
How do I convert Celsius to Fahrenheit?
Formula: °F = (°C × 9/5) + 32. For example, 100°C = (100 × 1.8) + 32 = 212°F. Enter any Celsius value in the tool and the Fahrenheit equivalent appears instantly.
How do I convert Fahrenheit to Celsius?
Formula: °C = (°F − 32) × 5/9. For example, 98.6°F = (98.6 − 32) × 0.5556 = 37°C. Enter any Fahrenheit value and all equivalents update instantly.
What is Kelvin used for?
Kelvin is the SI base unit of temperature used in science and engineering. 0 K (absolute zero) is the theoretical minimum temperature — −273.15°C or −459.67°F. Kelvin = Celsius + 273.15.
What is absolute zero?
Absolute zero is 0 Kelvin (−273.15°C / −459.67°F) — the temperature at which all molecular motion theoretically ceases. It has never been achieved experimentally, though temperatures within billionths of a degree have been reached in laboratory settings.