Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin, Rankine and 4 more units
Ideal room temperature
Understanding temperature scales
Three main scales: Celsius (°C), used in most countries; Fahrenheit (°F), used in the US and a few other countries; and Kelvin (K), the absolute scientific scale. 0 K is absolute zero (−273.15°C), the lowest possible temperature.
Conversion formulas
°F = (°C × 9/5) + 32 | °C = (°F − 32) × 5/9 | K = °C + 273.15. Practical benchmarks: 0°C = 32°F (freezing) | 37°C = 98.6°F (human body) | 100°C = 212°F (boiling) | 20°C = 68°F (comfortable room temperature).
Other historical scales
Rankine (°Ra): absolute scale based on Fahrenheit, used in American engineering. Delisle (°De): old inverted scale (100°De = 0°C). Newton (°N): created by Isaac Newton. Réaumur (°Ré): used in Europe in the 18th-19th centuries. Rømer (°Rø): the first calibrated scale in history.