Convert Rankine to Fahrenheit – Temperature Converter
This tool converts a temperature value from the Rankine scale (°R) to the Fahrenheit scale (°F). Rankine is an absolute temperature scale that uses the same degree magnitude as Fahrenheit but with its zero at absolute zero.
Use this converter for engineering, thermodynamics, HVAC calculations, and when reading instruments that report in Rankine. For high-precision work, follow calibration and uncertainty guidance described below and consult the cited standards.
Interactive Converter
Convert between rankine and fahrenheit with precision rounding.
Quick reference table
| Rankine | Fahrenheit |
|---|---|
| 1 °R | -458.67 °F |
| 5 °R | -454.67 °F |
| 10 °R | -449.67 °F |
| 25 °R | -434.67 °F |
| 50 °R | -409.67 °F |
| 100 °R | -359.67 °F |
Methodology
The Rankine and Fahrenheit scales share the same degree size; the only difference is the zero point. Conversion is therefore a fixed offset operation.
For everyday and engineering uses the conversion uses the constant 459.67, which aligns Rankine to the Fahrenheit zero point and is consistent with national metrology guidance.
For laboratory and legal metrology, apply instrument calibration, report measurement uncertainty, and follow NIST and relevant ISO/IEEE guidance when traceability and compliance are required.
Worked examples
Example 1: 491.67 °R → 491.67 − 459.67 = 32.00 °F.
Example 2: 540.00 °R → 540.00 − 459.67 = 80.33 °F.
Key takeaways
Conversion is a single fixed-offset arithmetic operation: subtract 459.67 from degrees Rankine to obtain degrees Fahrenheit. For regulated or high-accuracy work, combine this calculation with instrument calibration and uncertainty reporting.
Further resources
External guidance
Expert Q&A
What is Rankine and how does it relate to Fahrenheit?
Rankine is an absolute temperature scale where 0 °R is absolute zero. Each Rankine degree equals one Fahrenheit degree. The scales differ only by an additive constant: °R = °F + 459.67.
Is the conversion exact?
Mathematically the conversion uses the fixed constant 459.67. For numerical calculations this is treated as exact within the chosen precision, but measured temperatures are subject to instrument calibration and uncertainty which must be considered for high-accuracy applications.
How many decimal places should I use?
Match the number of decimal places to the resolution and uncertainty of your measurement device. For most engineering tasks 1–2 decimal places are common. For metrology and standards compliance, follow NIST and ISO recommendations and report uncertainty alongside the value.
Do I need to calibrate instruments when converting?
Yes. Conversion only changes units; it does not remove instrument bias or systematic error. Ensure your thermometer or sensor is calibrated and traceable to national standards if results are used for compliance, safety, or formal reporting.
Are there regulatory or safety considerations?
Workplace temperature measurements used for safety or compliance should follow occupational safety guidance and applicable standards. For example, heat exposure rules and calibration requirements may be specified by regulatory bodies.
Sources & citations
- NIST — Temperature and the International System of Units (SI) — https://www.nist.gov/pml/weights-and-measures/si-units-temperature
- ISO — Measurement of temperature (relevant ISO standards and guidance) — https://www.iso.org
- IEEE — Recommended practices for temperature measurement and instrumentation — https://standards.ieee.org
- OSHA — Heat and temperature workplace guidance — https://www.osha.gov/heat