Rankine (°R)
0
Equivalent temperature value
Accurate temperature conversion between kelvin and rankine — absolute scale units made simple
Convert kelvin to rankine (°R) instantly with exact calculations. Includes bidirectional conversion and full temperature breakdowns for science, engineering, and thermodynamics in 2026.
Professional temperature conversion for thermodynamics, engineering, and scientific calculations
Convert kelvin to rankine using the exact scientific relationship: 1 kelvin equals exactly 1.8 rankine (°R). Both are absolute temperature scales beginning at absolute zero, making this one of the cleanest unit conversions in thermometry — simply multiply kelvin by 1.8 to get rankine.
Switch seamlessly between kelvin to rankine and rankine to kelvin conversion modes. Get instant results with additional temperature breakdowns in Celsius (°C) and Fahrenheit (°F) — all from a single input value with no extra steps required.
Essential for thermodynamics coursework, aerospace engineering, cryogenics, chemical engineering, and any field working across SI (kelvin) and imperial (rankine) unit systems. Particularly useful when reading US engineering literature alongside international scientific standards.
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The kelvin (K) and the rankine (°R) are both absolute temperature scales — meaning they both start at absolute zero, the theoretical lowest possible temperature in the universe. Unlike Celsius and Fahrenheit, neither kelvin nor rankine uses negative values in normal thermodynamic work, because 0 K and 0 °R both represent the same physical point: absolute zero (−273.15°C / −459.67°F).
The key difference between the two scales is their degree size. The kelvin degree is the same size as the Celsius degree, while the rankine degree is the same size as the Fahrenheit degree. Since the Fahrenheit degree is exactly 1.8 times smaller than the Celsius degree, it follows that 1 K = 1.8 °R exactly. This simple multiplication factor makes kelvin-to-rankine one of the most straightforward temperature conversions, widely used in thermodynamics and fluid mechanics engineering.
1 K = 1.8 °R | 1 °R = 0.5556 K | Both scales start at absolute zero
Use this reference table to quickly look up common kelvin-to-rankine conversions including key thermodynamic reference points. All values use the exact factor of 1 K = 1.8 °R.
| Kelvin (K) | Rankine (°R) | Celsius (°C) | Fahrenheit (°F) |
|---|---|---|---|
| 0 K | 0 °R | −273.15 °C | −459.67 °F |
| 100 K | 180 °R | −173.15 °C | −279.67 °F |
| 200 K | 360 °R | −73.15 °C | −99.67 °F |
| 273.15 K | 491.67 °R | 0 °C (Freezing) | 32 °F |
| 293.15 K | 527.67 °R | 20 °C (Room Temp) | 68 °F |
| 300 K | 540 °R | 26.85 °C | 80.33 °F |
| 310.15 K | 558.27 °R | 37 °C (Body Temp) | 98.6 °F |
| 373.15 K | 671.67 °R | 100 °C (Boiling) | 212 °F |
| 500 K | 900 °R | 226.85 °C | 440.33 °F |
| 1,000 K | 1,800 °R | 726.85 °C | 1,340.33 °F |
| 5,000 K | 9,000 °R | 4,726.85 °C | 8,540.33 °F |
| 5,778 K | 10,400.4 °R | 5,504.85 °C (Sun Surface) | 9,940.73 °F |
Use this reverse reference table for rankine-to-kelvin lookups. All values use the exact factor of 1 °R = 0.5556 K (5/9 K).
| Rankine (°R) | Kelvin (K) | Celsius (°C) | Fahrenheit (°F) |
|---|---|---|---|
| 0 °R | 0 K | −273.15 °C | −459.67 °F |
| 100 °R | 55.56 K | −217.59 °C | −359.67 °F |
| 200 °R | 111.11 K | −162.04 °C | −259.67 °F |
| 459.67 °R | 255.37 K | −17.78 °C | 0 °F |
| 491.67 °R | 273.15 K | 0 °C | 32 °F (Freezing) |
| 527.67 °R | 293.15 K | 20 °C | 68 °F (Room Temp) |
| 540 °R | 300 K | 26.85 °C | 80.33 °F |
| 671.67 °R | 373.15 K | 100 °C | 212 °F (Boiling) |
| 900 °R | 500 K | 226.85 °C | 440.33 °F |
| 1,800 °R | 1,000 K | 726.85 °C | 1,340.33 °F |
The kelvin (K) is the SI base unit of thermodynamic temperature, named after Scottish physicist William Thomson, 1st Baron Kelvin (1824–1907). It is the primary temperature unit used in science worldwide. Unlike Celsius and Fahrenheit, kelvin has no degree symbol — temperatures are simply expressed as "K". The kelvin scale begins at absolute zero (0 K = −273.15°C), the point at which all molecular thermal motion theoretically ceases.
The rankine (°R) is an absolute temperature scale used primarily in the United States engineering community, named after Scottish engineer and physicist William John Macquorn Rankine (1820–1872). Like kelvin, the rankine scale starts at absolute zero — but its degree size matches the Fahrenheit degree rather than the Celsius degree. Rankine is the absolute version of Fahrenheit, just as kelvin is the absolute version of Celsius. It is still used in some areas of US aerospace, chemical, and mechanical engineering.
1 kelvin = exactly 1.8 rankine (°R). This is an exact value, not an approximation. The factor of 1.8 = 9/5 comes from the ratio between Celsius and Fahrenheit degree sizes. To convert K to °R, simply multiply by 1.8. To convert °R to K, divide by 1.8 (or multiply by 5/9).
Both kelvin and rankine begin at absolute zero — the same physical point. 0 K = 0 °R = −273.15°C = −459.67°F. This shared origin is what defines them as "absolute" scales and makes them the preferred temperature units for thermodynamic calculations where negative temperatures would be physically meaningless.
The key distinction between kelvin and rankine is degree size. One kelvin degree = one Celsius degree. One rankine degree = one Fahrenheit degree. Since 1°C = 1.8°F, it follows that 1 K = 1.8 °R. This means rankine values are always 1.8 times larger than their kelvin equivalents for any given temperature.
NASA and US aerospace engineers historically used rankine in thermodynamic equations when working in imperial units. Atmospheric re-entry temperatures, rocket engine combustion temperatures, and cryogenic fuel temperatures are sometimes reported in °R in legacy US technical documents, requiring kelvin-to-rankine conversion for cross-reference.
In thermodynamics, absolute temperature scales (K or °R) are essential for equations like the ideal gas law (PV = nRT), entropy calculations, and the Carnot efficiency formula. Using Celsius or Fahrenheit in these equations produces incorrect results. Both K and °R give correct results as long as the appropriate gas constant R is used.
William Rankine proposed his absolute temperature scale in 1859, just 11 years after William Thomson (Lord Kelvin) proposed the kelvin scale in 1848. Both scientists were working on the emerging field of thermodynamics simultaneously. While kelvin became the global SI standard, rankine remains entrenched in US imperial engineering traditions.
Unlike converting between Celsius and Fahrenheit (which requires both multiplication and addition of an offset), converting between kelvin and rankine requires only multiplication by 1.8. This is because both scales share the same zero point (absolute zero). There is no offset to add or subtract — °R = K × 1.8 is the complete formula. Do not add 459.67 or 273.15 when converting between K and °R directly.
Follow these simple steps to accurately convert any kelvin value to rankine:
The National Institute of Standards and Technology provides the official SI definitions for the kelvin unit, thermodynamic temperature standards, and accepted non-SI temperature units including rankine.
NIST Guide →NASA uses both kelvin and rankine in technical documentation. Their engineering standards library provides context for how rankine is applied in aerospace thermodynamics and propulsion calculations.
NASA Standards →The International Bureau of Weights and Measures (BIPM) maintains the official SI definition of the kelvin, updated in 2019 to be based on the Boltzmann constant rather than the triple point of water.
Visit BIPM →