Convert

Fahrenheit to Celsius

Temperature uses an offset. Fahrenheit and Kelvin are not pure factor units.

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Convert units with formula, context and precision

UnitCloud is a local measurement lab for everyday work, engineering, IT, energy, mobility and design. Every conversion shows result, formula, base unit, rounding and the common mistake.

What do you want to convert?

From1 °F

Result-17.22222222 °C

FactorOffset formula

Source basisBIPM SI Brochure · NIST Metric SI · NIST Guide to SI Appendix B

Examples

0132 °F = 0 °C

Example value from the reference table. Internal calculation uses stored factors; display output is rounded.

02Common mistake

Temperature uses an offset. Fahrenheit and Kelvin are not pure factor units.

03Base unit: °C

Temperature is first converted to Celsius and then moved to the target unit.

Table

Fahrenheit	Celsius
32	0
68	20
86	30
100	37.77777778
212	100

Formula

Temperature is first converted to Celsius and then moved to the target unit.

Sources

BIPM SI BrochureSI base units, prefixes and official SI context.NIST Metric SICurrent NIST SI overview after retirement of the historic SI Units site.NIST Guide to SI Appendix BNIST conversion-factor method and non-SI factors.

Related conversions

Celsius to Fahrenheit°C → °FTemperature Kelvin to CelsiusK → °CTemperature Celsius to Kelvin°C → KTemperature

Search and practice paths

FormulaTableExamplesCommon mistakeEveryday/engineeringExcel/CSVBatch converterPrint view

Factor origin

Factors come from the stored source family and are not derived from rounded display values.

Rounding rule

UnitCloud keeps calculating with stored factors and rounds only the displayed output by selected precision.

When not to use

Do not use as the sole basis for official, medical, safety-critical or contractual decisions.

Citation

Citation note: UnitCloud, conversion with formula, sources current as of May 2026. Temperature. Source basis: BIPM SI Brochure · NIST Metric SI · NIST Guide to SI Appendix B.

Common questions

What is the factor for Fahrenheit to Celsius?

Offset formula

Which formula does Fahrenheit to Celsius use?

Temperature is first converted to Celsius and then moved to the target unit.

When should I verify the result?

Do not use as the sole basis for official, medical, safety-critical or contractual decisions.