Temperature conversion
Rankine to Celsius converter
Convert °R to °C instantly, choose the displayed precision, and verify the result with the formula and reference table below.
Celsius (°C)
Rounded for display only; calculations retain full precision.
Rounding and precision rules
- Convr calculates first and rounds the displayed result only once, at the final step.
- The default is a maximum of 6 decimal places; trailing zeros are removed.
- Very small values that would appear as zero, and values of 10¹² or more, use scientific notation.
- Display precision is not measurement uncertainty. For scientific, engineering, or regulated work, retain only the digits justified by the source measurement.
Practical context
Understanding this conversion
Rankine values appear in some thermodynamics, aerospace, and process-engineering sources. Celsius provides a more familiar scale for communicating the corresponding temperature outside those systems.
Convert the degree size before shifting the zero point: multiply Rankine by 5/9, then subtract 273.15. Intermediate rounding should be avoided in technical work.
Reviewed August 16, 2026.
Calculation
Rankine to Celsius formula
°C = (°R × 5/9) − 273.15
Calculations retain full precision and the result is rounded only for display.
Worked example
For 25 °R, the result is -259.261111 °C. Substitute 25 °R into the formula to obtain -259.261111 °C.
Temperature scales use both scale and offset, so this conversion is not a simple multiplication.
Rankine to Celsius reference table
Common values rounded to a maximum of 6 decimal places.
| Rankine (°R) | Celsius (°C) |
|---|---|
| 1 °R | -272.594444 °C |
| 5 °R | -270.372222 °C |
| 10 °R | -267.594444 °C |
| 50 °R | -245.372222 °C |
| 100 °R | -217.594444 °C |
Understanding the units
About Rankine and Celsius
Rankine (°R)
The Rankine scale is an absolute temperature scale that uses Fahrenheit-sized degrees.
Celsius (°C)
The Celsius scale sets water’s freezing point at 0 °C and boiling point at 100 °C at standard atmospheric pressure.
When this conversion is useful
Rankine to Celsius conversion is useful for weather reports, cooking instructions, laboratory readings, engineering specifications, and scientific data. It lets you compare the same temperature reading across documents, tools, or standards that use different units.
Learn with Convr
Conversion guides
Celsius, Fahrenheit, Kelvin, and Rankine Explained
Learn how the four major temperature scales differ, why offsets matter, and which formulas convert between them correctly.
Read guide →FoundationsSignificant Figures and Rounding in Unit Conversions
Learn when to round conversion results, how significant figures preserve measurement meaning, and why more decimals do not guarantee more accuracy.
Read guide →Answers at a glance
Frequently asked questions
What is absolute zero in Celsius and Rankine?
Absolute zero is 0 °R and −273.15 °C.
What is 491.67 °R in Celsius?
Multiplying 491.67 by 5/9 and subtracting 273.15 gives 0 °C.
How does Convr round Rankine to Celsius results?
Convr keeps full numeric precision during the calculation and rounds only the displayed result. The default is a maximum of 6 decimal places, with selectable precision on this page.
Can I convert negative or decimal rankine values?
Yes. The converter accepts positive, negative, decimal, and scientific-notation values. Negative values are physically meaningful for some scales, such as temperature, but not for every measured quantity.
Keep converting