# Delisle to Rømer (°De to °Rø)

Source: https://www.unitconvertercalculator.com/temperature/delisle-to-romer/

To convert Delisle to Romer, use the formula: Ro = 60 - De x 7/20. The Delisle scale runs backwards compared to most temperature scales, with higher numbers indicating colder temperatures. 0 Delisle (boiling) = 60 degrees Romer, 150 Delisle (freezing) = 7.5 degrees Romer.

## Formula

°De via Kelvin to °Rø

## Conversion Table

| Delisle (°De) | Rømer (°Rø) |
|---|---|
| 0 °De | 60 °Rø |
| 50 °De | 42.500000000002 °Rø |
| 100 °De | 24.999999999998 °Rø |
| 150 °De | 7.5 °Rø |
| 200 °De | -9.9999999999982 °Rø |
| 250 °De | -27.500000000002 °Rø |
| 300 °De | -45 °Rø |
| 350 °De | -62.499999999998 °Rø |
| 400 °De | -80.000000000002 °Rø |
| 500 °De | -115 °Rø |
| 559 °De | -135.65 °Rø |

## Units

### Delisle (°De)

A historical inverted temperature scale invented by Joseph-Nicolas Delisle in 1732. Water boils at 0 °De and freezes at 150 °De. Higher numbers mean colder temperatures.

### Rømer (°Rø)

A temperature scale proposed by Ole Christensen Rømer in 1701. Water freezes at 7.5 °Rø and boils at 60 °Rø. It influenced Fahrenheit's scale development.

## Background

This conversion bridges the 18th-century Russian-adopted Delisle scale with the Romer scale. Historical Russian temperature records from the era of Catherine the Great and earlier require this conversion for comparison with modern scientific data expressed in Romer units.

## Good to Know

The Romer and Delisle scales are connected through the history of thermometry's development. Romer (1701) influenced Fahrenheit (1724), who influenced the broader tradition that Delisle (1732) contributed to. The conversion between Romer and Delisle connects two early thermometric experiments that, together with Celsius (1742) and Fahrenheit, defined the scientific understanding of temperature measurement in the 18th century.

## FAQ

### How do you convert Delisle to Romer?

Use the formula Ro = 60 - De x 7/20. 0 Delisle (boiling) = 60 degrees Romer, 150 Delisle (freezing) = 7.5 degrees Romer.

### Why does the Delisle scale run backwards?

Delisle measured how far below the boiling point a temperature was. Higher numbers meant further from boiling, which means colder. This inverted logic was logical for his laboratory work but confusing for everyday use.

### When would you need to convert Delisle to Romer?

When interpreting historical Russian scientific records from the 18th-19th centuries and converting them to Romer for modern analysis or comparison.

## Non-Frequently Asked Questions

### Were Romer and Delisle aware of each other's work?

Ole Romer created his scale around 1701 in Denmark, about 31 years before Delisle published his. Romer died in 1710, so he never saw the Delisle scale. But Romer's scale influenced both Fahrenheit (who visited Romer) and indirectly the broader thermometric tradition that Delisle worked within. The scales are intellectual cousins even if their creators never met.

### Is the Romer scale the most forgotten temperature scale?

It competes with the Newton scale for that distinction. Romer's scale was used briefly in Denmark and influenced Fahrenheit's design, but it was never widely adopted. Its most significant legacy is historical: Fahrenheit learned about thermometry from Romer, then created the scale that would dominate America for centuries. Romer is the teacher everyone forgot while celebrating the student.

### What is the oddest thing about the Romer scale?

Water freezes at 7.5 degrees Romer - not at zero, not at a round number, but at seven and a half. Romer chose this because he calibrated his thermometer using a brine solution that froze at 0 degrees Romer. Pure water's freezing point of 7.5 was simply where it fell on his scale. Fahrenheit borrowed this brine-zero concept, which is why water freezes at the equally arbitrary 32 degrees Fahrenheit.

## Related Articles

- [Why We Measure: The Deepest Urge in Human Civilisation](https://www.unitconvertercalculator.com/blog/why-we-measure)
- [The Map Is Not the Territory: Why Every Measurement Is Wrong](https://www.unitconvertercalculator.com/blog/the-map-is-not-the-territory)
- [Zero: The Most Dangerous Number in Measurement](https://www.unitconvertercalculator.com/blog/zero-the-most-dangerous-number-in-measurement)
- [The Speed of Everything: How We Measure From Glaciers to Light](https://www.unitconvertercalculator.com/blog/the-speed-of-everything)
- [Why Your Recipe Is Lying to You: The Chaos of Cooking Measurements](https://www.unitconvertercalculator.com/blog/why-recipe-measurements-are-unreliable)
- [When Measurements Go Wrong - Disasters, Blunders and Happy Accidents](https://www.unitconvertercalculator.com/blog/when-measurements-go-wrong)
- [The Surprising Stories Behind Everyday Units of Measurement](https://www.unitconvertercalculator.com/blog/stories-behind-measurement-units)
- [Metric vs. Imperial - The Complete Guide to the World's Two Measurement Systems](https://www.unitconvertercalculator.com/blog/metric-vs-imperial-complete-guide)
- [Temperature Conversion Guide for Travel, Cooking & Weather](https://www.unitconvertercalculator.com/blog/temperature-conversion-guide)

## See Also

- [Rømer to Delisle](https://www.unitconvertercalculator.com/temperature/romer-to-delisle/)