Formula – How to calculate Rømer
| | To Rømer (°Rø) | From Rømer (°Rø) |
| Celsius (°C) | (°C x 21/40) + 7.5 = °Rø | (°Rø – 7.5) x 40 / 21 = °C |
| Fahrenheit (°F) | ((°F – 32) x 7 / 24) + 7.5 = °Rø | ((°Rø – 7.5) x 24/7) + 32 = °F |
| Kelvin (K) | ((K – 273.15) x 21/40) + 7.5 = °Rø | ((°Rø – 7.5) x 40/21) + 273.15 = K |
| Rankine (°R) | ((°R – 491.67) x 7/24) + 7.5 = °Rø | ((°Rø – 7.5) x 24 / 7) + 491.67 = °R |
| Newton (°N) | (°N x 35/22) + 7.5 = °Rø | (°Rø – 7.5) x 22/35 = °N |
| Réaumur (°Ré) | (°Ré x 21/32) + 7.5 = °Rø | (°Rø – 7.5) x 32/21 = °Rø |
| Delisle (°De) | 60 – (°De x 7/20) = °Rø | (60 – °Rø) x 20/7 = De |
What is the Rømer temperature scale?
Rømer is a temperature scale based on the freezing point of brine as 0°and the boiling point of water as 60°. 7.5°Rø is the freezing point of water.
While the Rømer scale never became widely used, it was a precursor to the Fahrenheit scale (which used larger intervals for freezing and boiling points). The inventor of the scale also popularized the idea of a sealed tube to measure temperature (to avoid changes in air pressure).