# Delisle to Fahrenheit (°De to °F)

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

To convert Delisle to Fahrenheit, use the formula: F = 212 - De x 6/5. The Delisle scale, invented by French astronomer Joseph-Nicolas Delisle in 1732, runs in the opposite direction from most temperature scales - higher numbers mean colder temperatures. Zero Delisle is the boiling point of water (212 F), and 150 Delisle is the freezing point (32 F).

## Formula

°De via Kelvin to °F

## Conversion Table

| Delisle (°De) | Fahrenheit (°F) |
|---|---|
| 0 °De | 212 °F |
| 50 °De | 152.00000000001 °F |
| 100 °De | 91.999999999994 °F |
| 150 °De | 32 °F |
| 200 °De | -27.999999999994 °F |
| 250 °De | -88.000000000006 °F |
| 300 °De | -148 °F |
| 350 °De | -207.99999999999 °F |
| 400 °De | -268.00000000001 °F |
| 500 °De | -388 °F |
| 559 °De | -458.8 °F |

## 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.

### Fahrenheit (°F)

A temperature scale where 32°F is the freezing point and 212°F is the boiling point of water. Primarily used in the United States.

## Background

The Delisle scale was used in Russia for over a century, from the 1730s until Russia adopted Celsius in the mid-19th century. Russian meteorological records from this era require Delisle-to-Fahrenheit conversion for comparison with contemporary American weather data. At 100 Delisle (a mild 33.3 degrees Celsius), the Fahrenheit equivalent is 92 F - a warm but not extreme day.

## Good to Know

Joseph-Nicolas Delisle created his temperature scale in 1732 while working at the Russian Academy of Sciences for Tsar Peter the Great's successors. The scale became Russia's standard for over a century, meaning that early Russian scientific achievements in meteorology and physics were recorded in Delisle degrees. Converting these historical records to modern scales is essential for understanding the continuity of Russian scientific observation.

## FAQ

### How do you convert Delisle to Fahrenheit?

Subtract the Delisle value times 6/5 from 212. For example, 100 Delisle: 212 - (100 x 1.2) = 212 - 120 = 92 degrees Fahrenheit.

### Why does the Delisle scale run backwards?

Delisle originally designed his thermometer to measure only how far below the boiling point a temperature was. Higher numbers meant 'further from boiling,' which means colder. This inverted logic confused contemporaries and contributed to the scale's eventual abandonment.

### When was the Delisle scale used?

Primarily in Russia from the 1730s to the mid-1800s. Delisle worked at the Russian Academy of Sciences in St. Petersburg, where his scale became the local standard before being replaced by Celsius.

## Non-Frequently Asked Questions

### Is the Delisle scale the most confusing temperature scale ever invented?

It is a strong contender. An inverted scale where bigger numbers mean colder temperatures is counterintuitive to anyone raised on Celsius or Fahrenheit. Telling a Russian in 1750 that it was '200 Delisle outside' meant it was minus 33 Celsius - bitterly cold, despite the large positive number. The Delisle scale essentially trained people to fear high numbers.

### Could the Delisle scale work for weather forecasts?

Technically yes, but imagine the forecast: 'Tomorrow will reach a pleasant 100 degrees, dropping to a brisk 175 overnight.' Every number sounds alarming in Delisle because big numbers mean cold, and the range for normal weather (roughly 75 to 175 Delisle) uses numbers that sound extreme. Weather communication requires scales where the numbers match human intuition about severity.

### Did Delisle himself realize his scale was backwards?

Delisle designed his scale for scientific use where 'deviation from boiling point' was a natural reference. He was measuring mercury expansion, not communicating weather to the public. The scale worked perfectly for his laboratory purposes. It only became confusing when people tried to use it for everyday temperature communication, which was never its intended purpose.

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## See Also

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