Celsius to Réaumur Converter

Celsius (°C) is a temperature scale where 0°C is the freezing point of water and 100°C is the boiling point of water at standard atmospheric pressure. It is part of the metric system and widely used worldwide.

The Celsius scale was developed by Swedish astronomer Anders Celsius in 1742. Originally, he defined 0° as the boiling point and 100° as the freezing point of water, but this was later reversed. The scale was officially renamed from 'centigrade' to 'Celsius' in 1948 to honor its creator.

Celsius is the standard temperature scale used in most countries worldwide for weather reporting, cooking, medical applications, and scientific work. It's the official temperature scale in the International System of Units (SI) and is used in virtually all countries except the United States for everyday temperature measurements.

Réaumur (°Ré or °R) is a temperature scale where 0°Ré is the freezing point of water and 80°Ré is the boiling point of water at standard atmospheric pressure. Each degree Réaumur equals 1.25 degrees Celsius.

The Réaumur scale was developed by French scientist René Antoine Ferchault de Réaumur in 1730. He chose 80 degrees between the freezing and boiling points of water because his alcohol-based thermometer expanded by 80 parts per 1000 when heated from freezing to boiling water.

The Réaumur scale is largely obsolete and rarely used today. It may occasionally appear in historical scientific documents, some traditional European recipes (particularly in Germany and Russia), and certain specialized industrial applications. Most modern applications have switched to Celsius or Fahrenheit.