Convert Reaumur to Kelvin - Temperature Converter

This converter transforms a temperature value expressed on the Réaumur scale (°Ré) into the Kelvin scale (K). The Réaumur scale is a historical centigrade-derived scale still used occasionally in industry and historical data sets; Kelvin is the SI base unit for thermodynamic temperature.

The conversion is a fixed mathematical relationship and is appropriate for direct numeric translation. For metrology, laboratory work, and regulated reporting, follow instrument calibration and uncertainty guidance described below.

Updated Nov 23, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record d3eff335b2db • Reviewed by Fidamen Standards Committee

Interactive Converter

Convert between reaumur and kelvin with precision rounding.

Reaumur (°Ré)Kelvin (K)

Quick reference table

Reaumur	Kelvin
1 °Ré	274.4 K
5 °Ré	279.4 K
10 °Ré	285.65 K
25 °Ré	304.4 K
50 °Ré	335.65 K
100 °Ré	398.15 K

Methodology

Réaumur is defined so that 0 °Ré corresponds to 0 °C and 80 °Ré corresponds to 100 °C. The conversion uses exact rational scaling between Réaumur and Celsius, and the internationally recognized offset from Celsius to Kelvin.

This tool applies the direct algebraic conversion without applying measurement uncertainty or instrument-specific corrections. For regulated measurements consult NIST guidance on SI unit usage and relevant ISO standards on temperature measurement and calibration.

Key takeaways

Use Kelvin = (Réaumur × 5/4) + 273.15 for direct conversions.

For regulated measurements apply instrument calibration, document uncertainty, and follow NIST, ISO, IEEE, and OSHA guidance as appropriate.

Worked examples

0 °Ré → (0 × 5/4) + 273.15 = 273.15 K

80 °Ré → (80 × 5/4) + 273.15 = 373.15 K

-10 °Ré → (-10 × 5/4) + 273.15 = 260.65 K

F.A.Q.

Is the conversion exact?

The mathematical relationship Kelvin = (Réaumur × 5/4) + 273.15 is exact for scale definition. Practical measurements include instrument uncertainty, which this converter does not model.

How many decimal places should I report?

Report decimals consistent with measurement uncertainty and context. For laboratory reporting follow NIST and ISO guidance; for general use 2 decimal places is common (e.g., 273.15 K).

Does this tool handle negative Réaumur values?

Yes. The linear formula applies to negative values as well. Ensure physical plausibility when converting extreme temperatures near absolute zero.

What about calibration and regulatory compliance?

Use calibrated sensors and maintain traceability to national standards. Follow NIST SP 811 for SI usage, ISO standards for thermometry and calibration procedures, IEEE standards for instrumentation where applicable, and OSHA rules for workplace temperature monitoring and safety.

Does the converter account for sensor nonlinearity or environmental effects?

No. This converter performs a pure unit conversion. For sensor-specific corrections, compensation for radiative effects, or environmental corrections, apply instrument calibration curves or consult the sensor manufacturer and appropriate standards.

Sources & citations

NIST Special Publication 811 Guide for the Use of the International System of Units (SI) — https://www.nist.gov/pml/special-publication-811
NIST — Units, scales, and unit conversion information — https://physics.nist.gov/cuu/Units/
ISO (International Organization for Standardization) — standards catalogue — https://www.iso.org
IEEE Standards Overview — https://standards.ieee.org
OSHA — Occupational safety and health administration — https://www.osha.gov
ISO 80000-5:2019 — Thermodynamics — https://www.iso.org/standard/64976.html
NIST SP 330 — The International System of Units (SI) — https://www.nist.gov/pml/special-publication-330
BIPM SI Brochure (9th edition, 2019) — https://www.bipm.org/en/publications/si-brochure

Further resources

Related tools

External guidance

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: d3eff335b2db

What changed (latest)

v1.0.0 • 2025-11-23 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

Governance

Last updated: Nov 23, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
MINOR: New features or fields that do not change existing outputs for the same inputs.
PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

Verify formulas and unit definitions against primary standards or datasets.
Run golden-case regression suite and edge-case suite.
Record reviewer sign-off with credentials and scope.
Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

Uses exact unit definitions from the Fidamen conversion library.
Internal calculations use double precision; display rounding follows the unit's configured decimal places.
Not a substitute for calibrated instruments in regulated contexts.
Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-23 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 9ae1bc041970