Conversions

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Conversions

Rankine to Delisle Calculator.

Converts a temperature from Rankine to Delisle, a rarely used temperature scale where water boils at 0°De and freezes at 150°De.

Results update live as you type.
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Your inputs

How it works

  1. 1

    Enter the temperature in Rankine.

  2. 2

    Subtract 491.67 from the Rankine value.

  3. 3

    Multiply the result by 5/6.

  4. 4

    The result is the temperature in Delisle.

(491.67 - rankine) * 5 / 6

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 decreases as temperature increases.

How do I convert Rankine to Delisle manually?

Use the formula: °De = (491.67 - °R) × 5/6. For example, 500°R gives (491.67 - 500) × 5/6 = -6.94°De.

Can I convert Delisle back to Rankine?

Yes, the reverse formula is °R = 491.67 - (°De × 6/5).

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Results

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Temperature in Delisle

0°De

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Estimate for general guidance only — verify important decisions with an appropriate professional.

How it works

Converts a temperature from Rankine to Delisle, a rarely used temperature scale where water boils at 0°De and freezes at 150°De.

  1. Enter the temperature in Rankine.
  2. Subtract 491.67 from the Rankine value.
  3. Multiply the result by 5/6.
  4. The result is the temperature in Delisle.

Formulas

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

Rankine to Delisle

°De = (491.67 - °R) × 5/6

The Rankine scale is an absolute temperature scale with zero at absolute zero. The Delisle scale is inverted, so higher Rankine gives lower Delisle.

Example:

Input: °R = 671.67

Calculation: (491.67 - 671.67) × 5/6 = -180 × 5/6

Result: -150°De

Real-world use cases

Where this calculation shows up in everyday life.

Historical temperature conversion

Useful for converting historical temperature records that were originally measured in Delisle.

Example: Convert a 19th-century Delisle reading to Rankine.

Educational exercises

Helps students understand temperature scales and their relationships.

Example: Practice converting between Rankine and Delisle.

Scientific curiosity

Explore the properties of obscure temperature scales.

Example: Compare absolute zero in Rankine (0°R) to Delisle (491.67°De).

Tips and common mistakes

Tips

  • Remember that Delisle is an inverted scale: lower Delisle means higher temperature.
  • Absolute zero in Rankine is 0°R, which corresponds to 491.67°De.
  • Water freezes at 491.67°R (32°F) and boils at 671.67°R (212°F).
  • Use the calculator for quick conversions, but verify with manual math for critical work.

Common Mistakes to Avoid

  • Forgetting to subtract 491.67 before multiplying by 5/6.
  • Confusing the direction: higher Rankine gives lower Delisle.
  • Using the freezing point of water (491.67°R) as the boiling point.

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.