# Réaumur to Rankine (°Ré to °R)

Source: https://www.unitconvertercalculator.com/temperature/reaumur-to-rankine/

To convert Reaumur to Rankine, use the formula: R = Re x 9/4 + 491.67. The Reaumur scale is the historical European scale once standard in France and Germany, while the Rankine scale is the absolute Fahrenheit scale used in US thermodynamic engineering. Water freezes at 0 degrees Re (491.67 R) and boils at 80 degrees Re (671.67 R).

## Formula

°Ré via Kelvin to °R

## Conversion Table

| Réaumur (°Ré) | Rankine (°R) |
|---|---|
| -30 °Ré | 424.17 °R |
| -20 °Ré | 446.67 °R |
| -10 °Ré | 469.17 °R |
| 0 °Ré | 491.67 °R |
| 5 °Ré | 502.92 °R |
| 10 °Ré | 514.17 °R |
| 15 °Ré | 525.42 °R |
| 20 °Ré | 536.67 °R |
| 25 °Ré | 547.92 °R |
| 30 °Ré | 559.17 °R |
| 40 °Ré | 581.67 °R |
| 50 °Ré | 604.17 °R |
| 60 °Ré | 626.67 °R |
| 70 °Ré | 649.17 °R |
| 80 °Ré | 671.67 °R |
| 100 °Ré | 716.67 °R |
| 200 °Ré | 941.67 °R |

## Units

### Réaumur (°Ré)

A historical temperature scale where water freezes at 0 °Ré and boils at 80 °Ré. Named after René Antoine Ferchault de Réaumur. Once widely used in Europe.

### Rankine (°R)

An absolute temperature scale using Fahrenheit-sized degrees. 0 °R equals absolute zero. Used in some US engineering applications, especially thermodynamics.

## Background

The Reaumur scale was created by Rene Antoine Ferchault de Reaumur, 1730, once widespread in continental Europe. The Rankine scale was created by William Rankine, 1859, used in American aerospace and chemical engineering. Converting between them bridges different eras and different measurement philosophies in the history of thermometry.

## Good to Know

The history of temperature measurement is the history of scientific collaboration and competition across borders. The Reaumur scale (once widespread in continental Europe) and the Rankine scale (used in American aerospace and chemical engineering) represent different national contributions to solving the same fundamental problem: how to assign numbers to the sensation of hot and cold.

## FAQ

### How do you convert Reaumur to Rankine?

Use the formula R = Re x 9/4 + 491.67. At the freezing point of water: 0 Re = 491.67 R. At the boiling point: 80 Re = 671.67 R.

### When would you need to convert Reaumur to Rankine?

This conversion is needed when interpreting historical scientific records, comparing temperature data across different measurement traditions, or completing engineering calculations that mix temperature scales from different national standards.

### What are the key reference points for both scales?

Water freezes at 0 Re = 491.67 R. Water boils at 80 Re = 671.67 R. These two fixed points anchor both scales and provide easy verification of any conversion calculation.

## Non-Frequently Asked Questions

### What everyday temperature feels the same whether you measure it in Reaumur or Rankine?

Every temperature feels the same regardless of the scale you use to describe it. A comfortable room is comfortable whether you call it by its Reaumur or Rankine value. Temperature scales change the number, not the physics. Your skin cannot tell the difference between measurement systems.

### Is converting Reaumur to Rankine a skill anyone puts on their resume?

Unless you are applying to work in a museum of scientific instruments or writing the world's most comprehensive conversion website, this particular skill would raise more questions than it answers in a job interview. But it does demonstrate attention to detail and a fondness for completeness - qualities any employer should appreciate.

### What would happen if weather apps added Reaumur and Rankine to their display?

Weather apps already struggle to present temperature clearly in one or two scales. Adding Reaumur and Rankine would turn a simple forecast into a mathematics lecture. Users would see five or more numbers for the same temperature, causing decision paralysis about whether to bring a jacket. Simplicity in weather communication is not a luxury - it is a safety feature.

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## See Also

- [Rankine to Réaumur](https://www.unitconvertercalculator.com/temperature/rankine-to-reaumur/)