# Celsius to Rankine (°C to °R)

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

To convert Celsius to Rankine, multiply by 9/5 and add 491.67. The Rankine scale is an absolute temperature scale using Fahrenheit-sized degrees. This conversion is used in American engineering thermodynamics where absolute temperatures in Fahrenheit-based units are required.

## Formula

°R = (°C + 273.15) × 9/5

## Conversion Table

| Celsius (°C) | Rankine (°R) |
|---|---|
| -40 °C | 419.67 °R |
| -20 °C | 455.67 °R |
| -10 °C | 473.67 °R |
| 0 °C | 491.67 °R |
| 5 °C | 500.67 °R |
| 10 °C | 509.67 °R |
| 15 °C | 518.67 °R |
| 20 °C | 527.67 °R |
| 25 °C | 536.67 °R |
| 30 °C | 545.67 °R |
| 36 °C | 556.47 °R |
| 37 °C | 558.27 °R |
| 40 °C | 563.67 °R |
| 50 °C | 581.67 °R |
| 60 °C | 599.67 °R |
| 80 °C | 635.67 °R |
| 100 °C | 671.67 °R |
| 150 °C | 761.67 °R |
| 180 °C | 815.67 °R |
| 200 °C | 851.67 °R |
| 220 °C | 887.67 °R |
| 250 °C | 941.67 °R |
| 300 °C | 1031.67 °R |
| 500 °C | 1391.67 °R |
| 1000 °C | 2291.67 °R |

## Units

### Celsius (°C)

A metric temperature scale where 0°C is the freezing point and 100°C is the boiling point of water. Used worldwide except in the US.

### Rankine (°R)

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

## Background

Room temperature of 20°C equals 527.67°R. Water freezes at 491.67°R (0°C) and boils at 671.67°R (100°C). This conversion combines the Celsius-to-Fahrenheit conversion with the Fahrenheit-to-Rankine offset, but can be done in one step.

## Good to Know

Rankine is essentially 'Kelvin for Fahrenheit users'. It exists almost solely in American engineering education and some legacy industrial specifications.

## FAQ

### What is the formula for Celsius to Rankine?

The formula is: °R = (°C × 9/5) + 491.67. Alternatively, convert to kelvin first (add 273.15), then multiply by 9/5. Both methods give the same result.

### What is 0°C in Rankine?

0°C equals exactly 491.67°R. This is the freezing point of water expressed on the Rankine absolute temperature scale.

### When would I need Celsius to Rankine conversion?

This conversion is used in American engineering, particularly in thermodynamic calculations involving the ideal gas law, Carnot efficiency, and combustion analysis where Fahrenheit-sized absolute temperatures are standard.

## Non-Frequently Asked Questions

### Who uses Rankine besides engineers who refuse Kelvin?

Basically nobody else. Rankine is Fahrenheit's absolute scale, just as Kelvin is Celsius's absolute scale. American thermodynamics textbooks use it. Everyone else uses Kelvin. Rankine is the imperial system's last stand in thermodynamics.

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## See Also

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