Convert Celsius to Rankine
Convert Celsius to Rankine for engineering and thermodynamics. Apply (°C + 273.15) × 9/5.
How to Convert Celsius to Rankine
To convert Celsius to Rankine, add 273.15 to the Celsius value and multiply by 9/5.
Conversion Formula:
(value + 273.15) * 9/5Understanding the Conversion
Celsius to Rankine converts metric readings into the Fahrenheit-based absolute scale often used in U.S. thermodynamics, steam cycles, and combustion analysis. Rankine shares its degree size with Fahrenheit but starts at absolute zero, so the conversion requires both an offset and a scale factor.
The formula is °R = (°C + 273.15) × 9/5. First, shift Celsius to the absolute baseline by adding 273.15 (the Kelvin offset), then resize the result to Fahrenheit-sized degrees with the 9/5 multiplier. For reference, 0°C becomes 491.67°R, 100°C becomes 671.67°R, and −40°C becomes 419.67°R.
Use this conversion when working with U.S.-centric engineering calculations, Rankine-based charts, or legacy specifications that expect absolute Fahrenheit units. It is especially handy for Carnot efficiency, enthalpy charts, and combustion equations where Rankine is standard.
Mental shortcut: convert Celsius to Kelvin, then multiply Kelvin by 1.8. The converter handles both steps automatically with full precision.
Conversion Examples
Example: Convert 25°C to Rankine
- Step 1: 25 + 273.15 = 298.15.
- Step 2: 298.15 × 9/5 = 536.67.
- Step 3: Result is 536.67°R.
25°C ≈ 536.67°R
Shows a common room temperature on the Rankine scale.
Example: Convert 0°C to Rankine
- Step 1: 0 + 273.15 = 273.15.
- Step 2: 273.15 × 9/5 = 491.67.
- Step 3: Result is 491.67°R.
0°C = 491.67°R
Represents water’s freezing point expressed in Rankine.
Example: Convert -40°C to Rankine
- Step 1: -40 + 273.15 = 233.15.
- Step 2: 233.15 × 9/5 = 419.67.
- Step 3: Result is 419.67°R.
-40°C = 419.67°R
Illustrates subfreezing Celsius values as positive Rankine temperatures.
Conversion Formula
Celsius and Rankine differ in both zero point and degree size. Adding 273.15 moves to the absolute reference, and multiplying by 9/5 resizes Celsius degrees to the smaller Fahrenheit-sized Rankine degrees.
Conversion Chart
| Celsius | Rankine |
|---|---|
| -50 | 401.67 |
| -20 | 455.67 |
| 0 | 491.67 |
| 10 | 509.67 |
| 20 | 527.67 |
| 25 | 536.67 |
| 30 | 545.67 |
| 50 | 581.67 |
| 75 | 626.67 |
| 100 | 671.67 |
Quick Conversion Tip
Convert Celsius to Kelvin, then multiply by 1.8. It is the same as the combined formula.
Unit Definitions
Celsius (°C)
Metric temperature scale tied to water phase change points.
To Rankine, shift to absolute zero (add 273.15) then scale by 9/5. Direct to Fahrenheit uses (°C × 9/5) + 32.
Rankine (°R)
Absolute temperature scale using Fahrenheit-sized degrees, starting at absolute zero.
Rankine relates to Fahrenheit by °R = °F + 459.67. Convert from Kelvin by multiplying by 9/5.
Common Use Cases
- Thermodynamics and steam cycle calculations using Rankine.
- Combustion and heat engine analysis that requires °R inputs.
- Engineering coursework where Rankine is specified.
- Legacy U.S. industrial specifications written in Rankine.
- Comparing Celsius lab data to Rankine-based charts or diagrams.
- Quality checks where equipment documentation lists Rankine.
Frequently Asked Questions
Why do we multiply by 9/5 after adding 273.15?
Rankine uses Fahrenheit-sized degrees. After shifting to absolute zero, scaling by 9/5 aligns the degree size with Fahrenheit and Rankine.
Is Rankine used outside engineering?
Rankine is mainly used in U.S. engineering contexts, especially thermodynamics. Everyday weather and cooking rarely use Rankine.
What is the Rankine value for water boiling?
100°C equals 671.67°R, corresponding to 212°F plus 459.67.