Convert Rankine to Kelvin
Convert Rankine to Kelvin by multiplying by 5/9. Move from the Fahrenheit-based absolute scale to the SI absolute scale instantly.
How to Convert Rankine to Kelvin
To convert Rankine to Kelvin, multiply the Rankine value by 5/9.
Conversion Formula:
value * 5/9Understanding the Conversion
Rankine to Kelvin converts between two absolute temperature systems used in engineering and science. Because both scales share absolute zero, the only difference is degree size: Rankine uses Fahrenheit-sized degrees, and Kelvin uses Celsius-sized degrees. Converting is therefore a single scaling step.
The formula is K = °R × 5/9. For example, 491.67°R equals 273.15 K, 527.67°R equals 293.15 K, and 671.67°R equals 373.15 K. No offsets are involved because zero on both scales represents absolute zero.
Use this conversion when Rankine-based thermodynamic outputs need to feed into SI-based equations, when combining U.S. engineering data with international standards, or when educational materials shift between the two absolute scales. The calculator keeps precision so you can trust the values in sensitive calculations like efficiency, enthalpy, or gas properties.
Quick mental method: multiply by 0.5556 (approximate 5/9) to estimate, and rely on the converter for exact results.
Conversion Examples
Example: Convert 536.67°R to Kelvin
- Step 1: Multiply by 5/9: 536.67 × 5/9.
- Step 2: 536.67 × 0.5556 ≈ 298.15.
- Step 3: Result is 298.15 K.
536.67°R = 298.15 K
Room temperature expressed on the SI absolute scale.
Example: Convert 671.67°R to Kelvin
- Step 1: 671.67 × 5/9.
- Step 2: Calculation yields 373.15.
- Step 3: Result is 373.15 K.
671.67°R = 373.15 K
Equivalent to water boiling point on the Kelvin scale.
Example: Convert 419.67°R to Kelvin
- Step 1: 419.67 × 5/9.
- Step 2: Result is 233.15 K.
- Step 3: Shows absolute-zero alignment with Kelvin.
419.67°R = 233.15 K
Even positive Rankine values can represent subfreezing Kelvin temperatures.
Conversion Formula
Because both scales are absolute, only the degree size changes. Multiplying Rankine by 5/9 resizes the Fahrenheit-sized degrees to Celsius-sized degrees used by Kelvin.
Conversion Chart
| Rankine | Kelvin |
|---|---|
| 400 | 222.22 |
| 419.67 | 233.15 |
| 459.67 | 255.37 |
| 491.67 | 273.15 |
| 527.67 | 293.15 |
| 536.67 | 298.15 |
| 558.27 | 310.15 |
| 600 | 333.33 |
| 671.67 | 373.15 |
| 720 | 400 |
Quick Conversion Tip
Rankine to Kelvin is just × 0.5556. No offsets because both start at absolute zero.
Unit Definitions
Rankine (°R)
Absolute scale using Fahrenheit-sized degrees.
Multiply by 5/9 to reach Kelvin. Subtract 459.67 to reach Fahrenheit. Subtract 491.67 and multiply by 5/9 to reach Celsius.
Kelvin (K)
SI absolute temperature scale using Celsius-sized degrees.
Multiply Rankine by 5/9 to reach Kelvin. Convert Kelvin to Celsius by subtracting 273.15 and to Fahrenheit with (K − 273.15) × 9/5 + 32.
Common Use Cases
- Feed Rankine-based simulation data into SI equations.
- Compare U.S. engineering specs to international standards.
- Convert Rankine steam table outputs to Kelvin for research.
- Academic work demonstrating relationships between absolute scales.
- Quality checks when instruments output Rankine but models use Kelvin.
Frequently Asked Questions
Do I need to subtract anything?
No. Absolute zero is the same on both scales, so you only scale the degrees.
What if I need Celsius afterward?
After converting to Kelvin, subtract 273.15 to reach Celsius values.
Is 5/9 exact?
Yes. The ratio between Fahrenheit-sized and Celsius-sized degrees is exactly 5/9.