Fidamen

Convert Rankine to Celsius - Temperature Converter

This converter translates a single temperature value on the Rankine scale (°R) to the Celsius scale (°C). Rankine is an absolute temperature scale that uses Fahrenheit-sized degrees; Celsius is a relative temperature scale commonly used in science and industry.

Because the conversion is a fixed linear relationship, the calculator produces a direct numeric result for any numeric input. Use the guidance below for interpreting precision, reporting uncertainty, and ensuring measurement traceability when converting instrument readings.

This tool is intended for unit conversion only. For measuring actual temperature in the field or lab, use properly calibrated sensors and follow applicable standards for uncertainty reporting and instrument traceability.

Updated Nov 7, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record fb90de9e222a • Reviewed by Fidamen Standards Committee

Interactive Converter

Convert between rankine and celsius with precision rounding.

Quick reference table

RankineCelsius
1 °R-272.59 °C
5 °R-270.37 °C
10 °R-267.59 °C
25 °R-259.26 °C
50 °R-245.37 °C
100 °R-217.59 °C

Methodology

Rankine is an absolute scale tied to absolute zero and uses the Fahrenheit degree size. Celsius is tied to the Kelvin scale (C = K - 273.15). Converting Rankine to Celsius uses the exact linear relationship between these scales.

The calculator applies the internationally recognized arithmetic conversion; it does not attempt to estimate measurement error or instrument bias. For traceable measurements, follow standards such as ITS-90 and report uncertainty in accordance with NIST and ISO guidance.

Worked examples

0 °R → (0 × 5/9) − 273.15 = −273.15 °C (absolute zero)

491.67 °R → (491.67 − 491.67) × 5/9 = 0.00 °C

671.67 °R → (671.67 − 491.67) × 5/9 = 100.00 °C

F.A.Q.

Can I convert negative Rankine values?

No valid physical temperature on the Rankine scale is negative; Rankine is an absolute scale where 0 °R equals absolute zero. If a negative value is entered, treat it as a numeric input and the converter will return the corresponding Celsius number, but negative Rankine inputs are not physically meaningful.

How many decimal places should I report?

Match the number of significant figures to the precision of your measurement device. For simple unit conversions, display enough digits to preserve the original precision; avoid implying greater measurement accuracy than the instrument or data support.

Does this tool account for measurement uncertainty?

No. This converter performs a mathematical unit conversion only. To report uncertainty, quantify sensor and calibration uncertainties separately and follow NIST and ISO methods for uncertainty propagation.

Are there limits where the formula does not apply?

The algebraic conversion is exact for numeric values. However, for extremely large magnitudes or scientific applications requiring metrological rigor, consider numerical precision limits in software and follow ITS-90-based calibration for high-accuracy thermometry.

How should I calibrate instruments used to measure temperature?

Calibrate sensors against traceable standards and reference points per ITS-90 and ISO guidance. Keep calibration certificates and apply calibration corrections before converting instrument readings to another unit.

Sources & citations

Further resources

Versioning & Change Control

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

Record ID: fb90de9e222a

What changed (latest)

v1.0.0 • 2025-11-07 • 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

UI

v1.0.0

Governance

Last updated: Nov 7, 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 • 2025-11-07 • 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: 9bcb5aaf16f9