Rankine to Celsius, Fahrenheit & More Converter
Enter a temperature in degrees Rankine to convert it to Celsius, Fahrenheit, Kelvin, Newton, Delisle, Réaumur, and Rømer.
Rankine Temperature Conversion Tool
Rankine Temperature Conversion Formula
Where:
- \(R\) — input temperature in degrees Rankine (°R)
- \(C\), \(F\), and \(K\) — temperatures in Celsius (°C), Fahrenheit (°F), and kelvin (K)
- \(N\), \(D\), \(E\), and \(O\) — temperatures in Newton (°N), Delisle (°De), Réaumur (°Re), and Rømer (°Rø)
The calculator first finds the Celsius temperature, then uses it to calculate the historical scales. Fahrenheit and kelvin can also be calculated directly from Rankine.
Rankine to Celsius, Fahrenheit & More – Calculation Example
Example: enter the default value of 500 °R to find its equivalent on each temperature scale.
First, convert Rankine to Celsius:
\[C=\frac{500-491.67}{1.8}\approx 4.63\ ^\circ\mathrm{C}\]
Then calculate the other results using the formulas above:
\[\begin{aligned}F&=500-459.67=40.33\ ^\circ\mathrm{F} \\ K&=500/1.8\approx277.78\ \mathrm{K} \\ N&\approx1.53\ ^\circ\mathrm{N} \\ D&\approx143.06\ ^\circ\mathrm{De} \\ E&\approx3.70\ ^\circ\mathrm{Re} \\ O&\approx9.93\ ^\circ\mathrm{R\o}\end{aligned}\]
Result: 500 °R is approximately 4.63 °C, 40.33 °F, 277.78 K, 1.53 °N, 143.06 °De, 3.70 °Re, and 9.93 °Rø. The displayed values may have different rounding.
How to use the calculator
- Enter a nonnegative number in Temperature in Rankine. The default is 500 °R; decimals are allowed.
- Read the Celsius, Fahrenheit, and Kelvin results for the most commonly used temperature scales.
- Read Newton, Delisle, Reaumur, and Rømer if you need a historical scale. Use the unit beside each result to identify it.
To start with a different unit, use the Fahrenheit converter, Kelvin converter, or Celsius converter instead.
What a Rankine conversion tells you
Rankine is an absolute temperature scale: 0 °R is absolute zero, the theoretical lower limit of thermodynamic temperature. A change of one Rankine degree is the same size as a change of one Fahrenheit degree. That combination makes Rankine useful in some engineering calculations that use Fahrenheit-sized temperature intervals but require an absolute temperature.
Kelvin is also an absolute scale, but its increments are the same size as Celsius degrees. Because 1 K equals 1.8 °R as a temperature interval, converting an absolute Rankine temperature to kelvin requires dividing by 1.8. Neither kelvin nor Rankine needs an offset for that conversion. By contrast, converting Rankine to Fahrenheit requires subtracting 459.67 because the two scales have different zero points.
Celsius and Fahrenheit are often easier to interpret as everyday temperatures. For example, the default 500 °R is about 4.63 °C or 40.33 °F: a temperature above water’s freezing point at standard atmospheric pressure. The Newton, Delisle, Réaumur, and Rømer outputs express that same temperature on less commonly used scales. Delisle runs in the opposite direction from Celsius, so a warmer temperature has a lower Delisle reading.
Assumptions and practical tips
- Enter an absolute temperature, not a temperature difference. To convert an interval of 10 °R, for example, use 10 °F or 10/1.8 K as the interval; do not apply the absolute-temperature offsets.
- The input starts at 0 °R. Negative Rankine values are below absolute zero and are not valid ordinary thermodynamic temperatures.
- Rounding can make a displayed result differ slightly from a hand calculation. The calculator also uses decimal approximations in its Newton and Rømer formulas, so retain extra digits when checking intermediate steps.
- For context, water freezes at 491.67 °R and boils at 671.67 °R at standard atmospheric pressure. The boiling point changes with pressure; these are reference points, not fixed thresholds for every location.
If your source uses a historical scale, check its unit before entering a value here. For instance, a Delisle reading belongs in a Delisle converter, not in the Rankine input. The symbols also matter: °R denotes Rankine on this page, while °Rø denotes Rømer.
Frequently Asked Questions
How can I convert Rankine to Celsius by hand?
A convenient two-step method is to convert to Fahrenheit, then to Celsius. For example, 540 °R is \(540-459.67=80.33\ ^\circ\mathrm{F}\). Subtract 32 and multiply by \(5/9\): \((80.33-32)\times5/9=26.85\ ^\circ\mathrm{C}\). Keep the intermediate digits until the end to avoid extra rounding.
What is room temperature in degrees Rankine?
A commonly used room-temperature range of 20–25 °C is about 527.67–536.67 °R. There is no single universal room temperature: the intended value depends on the setting and the applicable standard. If a procedure specifies a particular temperature, use that value rather than assuming a typical range.
How do I convert Celsius or Fahrenheit back to Rankine?
For Celsius, use \(^\circ\mathrm{R}=(^\circ\mathrm{C}+273.15)\times1.8\). For Fahrenheit, use \(^\circ\mathrm{R}=^\circ\mathrm{F}+459.67\). For example, 32 °F equals 491.67 °R. These formulas convert temperature readings; a temperature change does not use the added offset.
Is 500 °R the same temperature as 500 K?
No. The two scales begin at absolute zero, but a kelvin is larger than a Rankine degree. A temperature of 500 K equals 900 °R, while 500 °R is about 277.78 K. When comparing readings, convert them to the same scale first rather than comparing their numbers.
Why might a hand calculation differ slightly from the Newton or Rømer result?
The calculator rounds displayed results and uses decimal approximations for two historical-scale formulas. For a more precise hand check, calculate Newton as \(^\circ\mathrm{N}=33(^\circ\mathrm{C})/100\) and Rømer as \(^\circ\mathrm{R\o}=7.5+21(^\circ\mathrm{C})/40\). Use an unrounded Celsius value until the final step.
Can a Delisle temperature be negative?
Yes. On the Delisle scale used here, 0 °De corresponds to 100 °C, and temperatures above 100 °C have negative Delisle readings. A negative Delisle result does not mean the temperature is below absolute zero; it reflects where zero falls on that scale and the direction in which its readings increase.
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