Historical Temperature ScalesReaumur to Celsius

Réaumur to Celsius

Methodology·How We Verify

Snapshot

1 Réaumur equals 1.25 Celsius.

Reference basis: This conversion uses a scale-and-offset equation (°C = °Ré * 1.25).
Example: For 20 Réaumur, the converted value equals 25 Celsius.

Interactive conversion

Converter Calculator

Decimals: 1.5 or 1,5. Fractions: 1/2. Scientific notation: 1e3. Write 1000 without grouping separators.

1.25 Celsius (°C)

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API and AI agent access

Réaumur to Celsius.

Machine-readable identifiers

Conversion family: historical-temperature-scales
Source unit: reaumur
Target unit: celsius

Use these identifiers in the API request. Sources and model limits also apply to software clients.

Example API request and response

POST /api/v1/convert

Request

{
  "family": "historical-temperature-scales",
  "value": 1,
  "from": "reaumur",
  "to": "celsius"
}

Essential response

{
  "ok": true,
  "conversion": {
    "family": "historical-temperature-scales",
    "value": 1,
    "from": "reaumur",
    "to": "celsius",
    "result": {
      "raw": 1.25,
      "display": "1.25"
    },
    "canonicalPath": "/historical-temperature-scales/reaumur-to-celsius/"
  }
}

API, OpenAPI and WebMCP documentation

Explanation

Use the exact affine transform for Réaumur to Celsius: multiply Réaumur by 1.25.

Method & Reference

Method basis: exact affine formula (scale + offset) shown in Snapshot.
Equation reference: °C = °Ré * 1.25
Consistency rule: forward and reverse pages use inverse equations to preserve scale reference points.

Reference note

This Réaumur to Celsius page uses explicit historical scale equations (scale + offset), not a simple multiplier.

Historical temperature scales are reconstructed from standard reference definitions.
Forward and reverse directions use inverse formulas, so each direction has its own dedicated page.

Common Conversion Values

Réaumur (°Ré)	Celsius (°C)
-40	-50
0	0
20	25
32	40
80	100
100	125

Questions & answers

Frequently Asked Questions

What is 1 Réaumur in Celsius?

1 Réaumur equals 1.25 Celsius on this page.

What equation does this Réaumur to Celsius page use?

This page uses °C = °Ré x 1.25, and the same equation drives the direct answer, calculator, table, and FAQ.

Is there a reverse page for Celsius to Réaumur?

Yes. The reverse direction has its own page at °C to °Ré, where the inverse equation is used so the mirror route stays numerically aligned.