Fidamen

Convert Celsius to Fahrenheit – Temperature Converter

This converter transforms a single temperature value in degrees Celsius (°C) into degrees Fahrenheit (°F) using the fixed mathematical relationship between the two scales. It is intended for quick calculations, educational purposes, lab notes, field measurements, and safety checks.

For measurement and safety applications, be mindful that the numerical conversion is exact for arithmetic values but real-world temperature readings may include sensor error, calibration offsets, and uncertainty. Consult calibration and traceability guidance when using converted values for compliance, health and safety, or instrumentation.

Updated Nov 11, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 9b392a2e513b • Reviewed by Fidamen Standards Committee

Interactive Converter

Convert between celsius and fahrenheit with precision rounding.

Quick reference table

CelsiusFahrenheit
1 °C33.8 °F
5 °C41 °F
10 °C50 °F
25 °C77 °F
50 °C122 °F
100 °C212 °F

Methodology

The conversion uses the internationally recognized linear relationship between the Celsius and Fahrenheit scales. The formula F = C × 9/5 + 32 converts Celsius to Fahrenheit; the inverse is C = (F − 32) × 5/9.

When applied to measurement results, conversion is independent of the measurement instrument. However, good practice requires that the original temperature measurement be traceable to standards (for example NIST-traceable calibration) and that uncertainty be reported per ISO guidance. For occupational health thresholds and heat-stress limits, follow relevant regulatory guidance such as published OSHA recommendations.

Worked examples

0 °C → (0 × 9/5) + 32 = 32 °F

100 °C → (100 × 9/5) + 32 = 212 °F

-40 °C → (-40 × 9/5) + 32 = -40 °F (the two scales coincide at -40)

Absolute zero: -273.15 °C → (-273.15 × 9/5) + 32 = -459.67 °F

F.A.Q.

Is the conversion exact?

The mathematical conversion using F = C × 9/5 + 32 is exact for numerical values. Real-world temperature measurements include instrument error and uncertainty; converted reported values inherit that uncertainty. For metrology or regulatory work, include measurement uncertainty and calibration status per relevant standards.

How many decimal places should I use?

Choose decimal places based on the precision of your original measurement. Do not imply greater precision than your instrument provides. For many general uses, one decimal place is sufficient; for lab or engineering work, follow your instrument's specification and report uncertainty per ISO 17025 guidance.

Why does the formula use 9/5 and 32?

The factor 9/5 arises from the ratio of the size of the Fahrenheit degree to the Celsius degree; adding 32 accounts for the different zero points of the two scales. This relationship is fixed and derived from the definitions of the scales.

Are there regulatory considerations for converted temperatures?

Yes. When converted temperatures are used for safety limits, compliance, or health assessments, ensure that measurement instruments are calibrated and traceable to standards such as those published by NIST and that you follow applicable workplace or industry regulations (for example OSHA heat guidelines).

What about sensor calibration and traceability?

Calibration establishes a link between an instrument's readings and reference standards. For authoritative measurement, ensure sensors are calibrated at appropriate intervals, document traceability (for example to NIST), and include calibration uncertainty in any reported converted value.

Sources & citations

Further resources

Versioning & Change Control

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

Record ID: 9b392a2e513b

What changed (latest)

v1.0.0 • 2025-11-11 • 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 11, 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 • 2025-11-11 • 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: 0e43426e55e6