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Conversions

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Conversions

Delisle to Fahrenheit Calculator.

Converts a temperature from the Delisle scale to Fahrenheit. The Delisle scale is an obsolete temperature scale where water boils at 0 degrees and freezes at 150 degrees.

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Your inputs

How it works

  1. 1

    Enter the temperature in degrees Delisle.

  2. 2

    Multiply the Delisle value by 6/5.

  3. 3

    Subtract the result from 212.

  4. 4

    The result is the temperature in degrees Fahrenheit.

212 - (delisle * 6 / 5)

Frequently asked questions

What is the Delisle scale?

The Delisle scale (°De) is an obsolete temperature scale where water boils at 0°De and freezes at 150°De. It was invented by French astronomer Joseph-Nicolas Delisle in 1732.

How do I convert Fahrenheit to Delisle?

Use the inverse formula: Delisle = (212 - Fahrenheit) * 5/6. For example, 32°F equals 150°De.

Why is the Delisle scale inverted?

Delisle's thermometer had a glass bulb with mercury that expanded with heat, so higher temperatures caused the mercury to rise, but the scale was marked with 0 at the boiling point and 150 at the freezing point, making it decrease with increasing temperature.

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Temperature in Fahrenheit

92°F

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How it works

Converts a temperature from the Delisle scale to Fahrenheit. The Delisle scale is an obsolete temperature scale where water boils at 0 degrees and freezes at 150 degrees.

  1. Enter the temperature in degrees Delisle.
  2. Multiply the Delisle value by 6/5.
  3. Subtract the result from 212.
  4. The result is the temperature in degrees Fahrenheit.

Formulas

The math behind this calculator, written out so you can verify the result.

Delisle to Fahrenheit

°F = 212 - (°De × 6/5)

The Delisle scale is defined such that 0°De = 212°F (boiling point of water) and 150°De = 32°F (freezing point). The linear relationship gives this conversion formula.

Real-world use cases

Where this calculation shows up in everyday life.

Historical temperature records

Convert old temperature readings recorded in Delisle to modern Fahrenheit for comparison.

Example: A record of 50°De converts to 152°F.

Educational demonstrations

Teach about temperature scales and their historical development by converting between Delisle and Fahrenheit.

Example: Show that 0°De is boiling and 150°De is freezing.

Science fiction and literature

Interpret temperatures mentioned in historical texts or fictional works that use the Delisle scale.

Example: A story mentioning 120°De corresponds to 68°F.

Tips and common mistakes

Tips

  • Remember that the Delisle scale is inverted: higher Delisle values mean lower temperatures.
  • For quick mental estimates, note that 1°De change equals 1.2°F change.
  • Use the formula °F = 212 - (°De × 1.2) for a simpler approximation.
  • Check your result: 0°De should give 212°F and 150°De should give 32°F.

Common Mistakes to Avoid

  • Forgetting that the scale is inverted and adding instead of subtracting.
  • Using the wrong factor: the correct multiplier is 6/5 (or 1.2), not 5/6.
  • Confusing the freezing and boiling points: 0°De is boiling, 150°De is freezing.

Assumptions and limitations

  • Use the stated inputs and units.
  • Results are estimates for planning and education.
  • Check measurements and source data before making an important decision.