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Kelvin to Rankine Converter
↔ Convert °R to K instead

Common Conversions

K °R
0 0
50 90
100 180
200 360
273.15 491.67
298.15 536.67
300 540
373.15 671.67
400 720
500 900
1000 1800
5000 9000

Why this conversion matters in chemistry

Kelvin and Rankine are siblings — both absolute temperature scales starting at absolute zero. The only difference is the size of the degree: a Kelvin equals a Celsius degree, and a Rankine equals a Fahrenheit degree. Since both scales share the same zero, the conversion is just multiplication, no offset needed. Most chemistry stays in Kelvin; US engineering thermodynamics — steam tables, combustion analyses, gas-law calculations using R in English units — works in Rankine. Multiplying by 1.8 lets a 298.15 K standard reference temperature land at 536.67 °R when the calculation downstream needs English absolute units.

Formula

°R = K × 1.8

Worked Examples

273.15 K = 491.67 °R

The freezing point of water — the value where the two absolute scales intersect a familiar physical anchor.

0 K = 0 °R

Absolute zero — where both scales start, by construction. The shared origin is what makes the conversion a pure multiplication.

373.15 K = 671.67 °R

The boiling point of water at 1 atm, the other classic calibration anchor.

298.15 K = 536.67 °R

Standard reference temperature — the value behind tabulated thermodynamic standard states in both unit systems.

Frequently Asked Questions

How do I convert Kelvin to Rankine?
Multiply by 1.8, or equivalently 9/5. So 300 K becomes 540 °R. Because both scales start at absolute zero, there's no offset — just a scaling factor.
What is the Rankine scale?
Rankine is an absolute temperature scale with Fahrenheit-sized degrees. Zero Rankine is absolute zero, by construction. It was proposed by William John Macquorn Rankine in 1859 — Rankine is to Fahrenheit what Kelvin is to Celsius.
When does a chemist actually meet Rankine?
Mostly when working from US engineering thermodynamics references — steam tables, combustion calculations, gas-law problems written for the form of R that uses English units (BTU/lb-mol·°R). Anything in modern chemistry research stays in Kelvin.
Why does the factor 1.8 work cleanly?
Because a Kelvin spans 1.8 Rankine degrees by definition — same physical interval, smaller-sized degree on the Rankine side. With both scales sharing absolute zero, the only thing the conversion has to do is rescale the degree size.