What is Rankine to Kelvin Conversion?

Converting Rankine to Kelvin translates between two absolute temperature scales. Both start at absolute zero, but Rankine uses Fahrenheit-sized degrees while Kelvin uses Celsius-sized degrees.

Two Absolute Scales

Understanding the relationship:

Same zero point: 0°R = 0 K = absolute zero
Different degree size: 1.8°R = 1 K
Kelvin: International scientific standard (SI)
Rankine: Used in some US engineering contexts

The Simple Formula

The conversion is straightforward: K = °R × 5/9 (or °R ÷ 1.8). Since both scales start at absolute zero, the relationship is a simple ratio.

When to Use This Conversion

Convert Rankine to Kelvin when you encounter Rankine temperatures and need them in the international SI standard, such as for scientific publications or international collaboration.

How to Use the Rankine to Kelvin Converter

Conversion Steps

Enter Rankine value - Type the temperature in the left field
Read Kelvin result - See the SI standard value on the right
Copy if needed - Use the copy button to save the result

Common Temperature Conversions

0°R = 0 K - Absolute zero
180°R = 100 K - Very cold
492°R = 273 K - Around freezing
527°R = 293 K - Room temperature
672°R = 373 K - Around boiling
900°R = 500 K - High temperature

Mental Math

To estimate, divide Rankine by 2 and add 10%. Example: 540°R ÷ 2 = 270, plus 10% (27) = 297 K. Exact: 300 K.

Understanding the Result

Since both scales start at zero, Kelvin values are always 5/9 (about 0.556) times the corresponding Rankine value.

Converter Features

Accurate Results

Results display to 4 decimal places, providing the precision needed for technical and scientific applications.

Useful Reference Points

Quick reference shows the relationship:

0°R = 0 K - Absolute zero
492°R ≈ 273 K - Freezing point
527°R ≈ 293 K - Room temperature
672°R ≈ 373 K - Boiling point

Real-Time Calculation

Kelvin values update instantly as you type, enabling quick conversion of multiple temperatures.

Bidirectional Swap

Use the swap button to convert Kelvin back to Rankine (multiply by 1.8).

Copy Functionality

One-click copy puts the Kelvin value on your clipboard, ready for scientific calculations or documentation.

Frequently Asked Questions

What is the formula to convert Rankine to Kelvin?

The formula is K = °R × 5/9 (or °R ÷ 1.8). Divide the Rankine value by 1.8 to get Kelvin.

Why is the ratio 5/9?

Celsius degrees are 5/9 the size of Fahrenheit degrees. Since Kelvin uses Celsius-sized degrees and Rankine uses Fahrenheit-sized degrees, the same ratio applies.

Do both scales start at absolute zero?

Yes, both Rankine and Kelvin define zero as absolute zero—the theoretical temperature where all molecular motion stops. This makes the conversion a simple ratio.

What is room temperature in both scales?

Room temperature of about 20°C equals approximately 527°R or 293 K.

Which scale should I use?

Kelvin is the international SI standard and preferred for scientific work. Rankine is mainly used in some US engineering contexts.

Is this conversion exact?

Yes, K = °R × 5/9 is mathematically exact. Both scales are precisely defined relative to absolute zero.

Rankine to Kelvin