Convert celsius to delisle easily.

Ever stumbled upon an old Russian weather report or a 18th-century science text and wondered, “What on Earth is a Delisle degree?” You’re not alone. While most of us are cozy with Celsius and Fahrenheit, the Delisle scale is that quirky relative at the family reunion—unexpected, a bit confusing, but undeniably interesting. Let’s unravel this historical oddity and see how it stacks up against our modern Celsius.

Unit definitions

What is a celsius (°c)?

• Description: The Celsius scale, used worldwide, sets water’s freezing point at 0°C and boiling point at 100°C under standard atmospheric pressure.
• Symbol: °C
• Common uses: Daily weather forecasts, cooking, scientific research.
• Definition: 1°C equals 1/100 of the interval between water’s freezing and boiling points.

What is a delisle (°de)?

• Description: Created in 1732 by French astronomer Joseph-Nicolas Delisle, this scale originally ran backwards—0°De represented boiling water, while 150°De marked freezing. Later revisions flipped it to align intuitively with colder temperatures.
• Symbol: °De
• Common uses: Historical records, niche scientific studies.
• Definition: Each degree Delisle equals -2/3 of a Celsius degree.

Conversion formula

To convert celsius to delisle:

°De = (100 − °C) × 1.5

For delisle to celsius:

°C = 100 − (°De ÷ 1.5)

Example calculations

1. Room temperature (20°C to Delisle):
   (100 − 20) × 1.5 = 120°De
   Wait, 20°C feels mild, but 120°De? Remember—higher Delisle numbers mean colder temps!
2. Russian winter (-30°C to Delisle):
   (100 − (-30)) × 1.5 = 195°De
   Now that’s what you’d call a deep freeze in Saint Petersburg terms.

Conversion tables

Celsius to delisle

Delisle to celsius

Historical background

Joseph-Nicolas Delisle didn’t set out to confuse future generations. In 1732, he devised his scale for a mercury thermometer commissioned by teh Russian Academy of Sciences. Oddly enough, his original version had boiling water at 0°De and freezing at 150°De—a true inversion of logic. It gained traction in Russia (where Delisle worked for decades) but fell out of favor after Celsius’s more intuitive system emerged. By the 19th century, even Russia had moved on, though you’ll still spot Delisle in antique meteorological logs.

Interesting facts?

1. Scale flip-flop: Delisle’s student Josias Weitbrecht reversed the scale posthumously, making 0°De the boiling point we use today.
2. Long-lived in Siberia: Some remote Russian stations used Delisle thermometers until the 1880s.
3. Negative madness: The scale can technically go below 0°De—imagine -10°De being hotter than boiling water!
4. Newton’s influence: Delisle corresponded with Isaac Newton about temperature scales, though they disagreed on fixed points.
5. One-upmanship: Delisle’s 240-degree scale (pre-revision) aimed to outdo Fahrenheit’s 180-degree water interval.

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