Convert Rankine to Planck Temperature
Convert degrees rankine to planck temperatures instantly. 1 °R = 3.921244e-33 T_P — use the live calculator, the exact formula, a reference-temperature table and worked examples. Also check the Planck Temperature to Rankine converter for the reverse conversion.
Units explained
Rankine
The degree Rankine (°R) is the absolute counterpart of the Fahrenheit scale: 0 °R is absolute zero, and one degree Rankine is exactly the same size as one degree Fahrenheit (5/9 of a kelvin). Water freezes at 491.67 °R.
Named for William John Macquorn Rankine, the Scottish engineer and physicist who proposed an absolute scale built from Fahrenheit-sized degrees, paralleling Kelvin's absolute scale built from Celsius-sized degrees.
Used mainly in United States aerospace, thermodynamics, and power-plant engineering, where calculations demand absolute temperature but legacy data, instruments, and codes are in Fahrenheit.
Proposed by W. J. M. Rankine at the University of Glasgow in 1859, eleven years after Lord Kelvin's absolute scale of 1848.
Planck Temperature
The Planck temperature (T_P) is the natural unit of temperature, about 1.416784×10³² kelvins, constructed purely from the fundamental constants ħ, c, G, and k. It is widely regarded as the highest temperature at which known physics remains meaningful.
Arises from Max Planck's 1899 system of natural units, which combines the speed of light, the gravitational constant, the reduced Planck constant, and the Boltzmann constant into universal base quantities independent of any human artifact.
Cosmology and quantum-gravity research, where it marks the temperature of the universe roughly one Planck time after the Big Bang. No laboratory process approaches even a trillionth of a trillionth of it.
Defined within Max Planck's natural-unit system proposed in Germany in 1899; the modern recommended value (1.416784×10³² K) is maintained by the CODATA fundamental-constants adjustment.
Rankine to Planck Temperature conversion formula
Note: this conversion uses the CODATA recommended value of the Planck temperature (1.416784×10³² K), which carries a small experimental uncertainty from the gravitational constant G.
The exact relationship between degrees rankine and planck temperatures:
To convert degrees rankine to planck temperatures, multiply the value in degrees rankine by 3.921244e-33. To reverse, multiply the value in planck temperatures by 2.550211e+32.
Both units count upward from absolute zero, so 0 °R = 0 T_P and the relationship is a pure ratio.
How to use this converter
Type a value into the calculator. The result in planck temperatures updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Planck Temperature to Rankine converter for the reverse direction.
Step-by-step: convert degrees rankine to planck temperatures
- Write down the temperature in degrees rankine (°R).
- Multiply the value in degrees rankine by 3.921244e-33.
- The result is the same temperature expressed in planck temperatures (T_P).
- To reverse, multiply the value in planck temperatures by 2.550211e+32 — or open the Planck Temperature to Rankine converter.
Worked examples
Example 1 — Convert 1 °R to T_P:
1 × 3.921244e-33 = 3.921244e-33 T_P
Example 2 — Convert 100 °R to T_P:
100 × 3.921244e-33 = 3.921244e-31 T_P
Rankine to Planck Temperature conversion table
Physically meaningful reference temperatures, from absolute zero to the surface of the Sun, converted from degrees rankine to planck temperatures:
| Rankine [°R] | Planck Temperature [T_P] | Reference point |
|---|---|---|
| 0 | 0 | Absolute zero |
| 419.67 | 1.645628e-30 | Where Celsius and Fahrenheit coincide (−40°) |
| 459.67 | 1.802478e-30 | Zero Fahrenheit (0 °F) |
| 491.67 | 1.927958e-30 | Water freezes (0 °C / 32 °F) |
| 491.688 | 1.928029e-30 | Triple point of water |
| 509.67 | 1.99854e-30 | Cool day (10 °C / 50 °F) |
| 527.67 | 2.069123e-30 | Room temperature (20 °C / 68 °F) |
| 536.67 | 2.104414e-30 | Standard laboratory temperature (25 °C) |
| 545.67 | 2.139705e-30 | Hot day (30 °C / 86 °F) |
| 558.27 | 2.189113e-30 | Human body temperature (37 °C / 98.6 °F) |
| 563.67 | 2.210288e-30 | Heat-wave day (40 °C / 104 °F) |
| 581.67 | 2.28087e-30 | Hot tap water (50 °C / 122 °F) |
| 671.67 | 2.633782e-30 | Water boils (100 °C / 212 °F) |
| 815.67 | 3.198441e-30 | Moderate baking oven (180 °C / 356 °F) |
| 10400.4 | 4.07825e-29 | Surface of the Sun (≈5,505 °C) |
Frequently asked questions
How many planck temperatures is 1 degree rankine?
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How many planck temperatures is 100 degrees rankine?
Can a temperature be below absolute zero?
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Sources & references
Conversion relationship (1 °R = 3.921244e-33 T_P) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- BIPM — International Temperature Scale of 1990 (ITS-90)
The internationally agreed practical temperature scale, defining fixed points (including the triple point of water at 273.16 K) and interpolation instruments used by national metrology institutes for thermometer calibration worldwide.
- CODATA Internationally Recommended Values of the Fundamental Physical Constants
Committee on Data of the International Science Council; authoritative source for the masses of fundamental particles (electron, proton, neutron) and the atomic mass constant.