Convert Rankine to Kelvin - Temperature Converter
This converter transforms temperatures expressed in degrees Rankine (°R) to Kelvin (K). The conversion is a fixed mathematical scaling because both Rankine and Kelvin are absolute temperature scales; no offset is required.
Use this conversion for scientific calculations, engineering work, data logging, and unit standardization. While the mathematical conversion is exact, note that measured temperatures carry instrument uncertainty and may require calibration traceable to recognized standards.
Interactive Converter
Convert between rankine and kelvin with precision rounding.
Quick reference table
| Rankine | Kelvin |
|---|---|
| 1 °R | 0.56 K |
| 5 °R | 2.78 K |
| 10 °R | 5.56 K |
| 25 °R | 13.89 K |
| 50 °R | 27.78 K |
| 100 °R | 55.56 K |
Methodology
Rankine and Kelvin are absolute scales where 0 corresponds to absolute zero. A Rankine degree is defined as 1/°R = 5/9 of a Kelvin, so the conversion is a simple multiplicative factor.
This tool applies the exact scaling factor to the input value and then formats the result. For lab or regulatory uses, combine the numeric conversion with the measurement uncertainty and calibration certificate information from accredited laboratories or national metrology institutes.
Worked examples
Example 1: 0 °R → 0 K (absolute zero)
Example 2: 540 °R → 540 × 5/9 = 300 K
Example 3: 671.67 °R → 671.67 × 5/9 = 373.15 K (approx. 100 °C)
Key takeaways
Use K = °R × 5/9 for direct conversion. The mathematical conversion is exact, but measurement uncertainty and calibration determine practical accuracy.
For regulated or precision work, ensure instruments are calibrated to traceable standards and report converted values with uncertainty and supporting calibration documentation.
Expert Q&A
Is the Rankine to Kelvin conversion exact?
The mathematical relationship K = R × 5/9 is exact by definition of the scales. However, measured temperatures include instrument uncertainty, so report converted values together with the measurement uncertainty when precision matters.
Can I convert negative Rankine values?
Rankine is an absolute temperature scale where 0 °R corresponds to absolute zero; physically meaningful temperatures are non-negative. Negative inputs are mathematically convertible but represent non-physical values and should be treated cautiously.
How many decimal places should I keep?
Choose precision based on measurement uncertainty and downstream calculations. For display, 2–4 significant figures are common; for engineering or scientific calculations, keep extra digits and round only at the end.
Do I need to consider calibration or standards?
Yes. The conversion is numeric, but the accuracy of a converted reading depends on instrument calibration. Use instruments calibrated traceable to national standards (for example, NIST) and include calibration uncertainty in any compliance or reporting.
Are there regulatory limits tied to Kelvin values?
Regulatory agencies may set temperature-related exposure or process limits in different units. Convert values accurately for compliance checks, and consult the relevant regulatory guidance for how to report measurements and uncertainties.
Sources & citations
- NIST Special Publication 811 - Guide for the Use of the International System of Units (SI) — https://www.nist.gov/pml/special-publication-811
- ISO 80000 series — Quantities and units (general reference) — https://www.iso.org/iso-80000-1.html
- OSHA heat stress information and workplace guidance — https://www.osha.gov/heat-exposure
- IEEE Standards Association (standards catalog and guidance) — https://standards.ieee.org