Convert

Joule to Kilocalorie

Exact answer: 1 J = 0.000239005736 kcal (exact defined factor)

Joule and Kilocalorie describe the same quantity from the Energy family but come from different systems of units. The factor is defined exactly. Energy appears in electricity tariffs, food labels, heating costs and technical datasheets.

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What do you want to convert?

From1,000 J

Result0.239006 kcal

Factor1 J = 0.000239005736 kcal

Source basisBIPM SI Brochure · NIST Guide to SI Appendix B

Examples

011,000 J = 0.239006 kcal

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

02Common mistake

Food calories are kilocalories. Utility bills use kilowatt-hours. Both are energy units, but in different contexts.

03Base unit: J

1 J = 0.000239005736 kcal. Joule is the base unit of the family, so the value is converted directly.

Table

Joule to Kilocalorie
Joule	Kilocalorie
1,000	0.239006
4,184	1
10,000	2.390057
100,000	23.900574
1,000,000	239.005736
10,000,000	2,390.057361

Formula

1 J = 0.000239005736 kcal. Joule is the base unit of the family, so the value is converted directly.

Sources

BIPM SI BrochureSI base units, prefixes and official SI context.NIST Guide to SI Appendix BNIST conversion-factor method and non-SI factors.

Related conversions

Kilowatt-hour to JoulekWh → JEnergy Joule to Kilowatt-hourJ → kWhEnergy Kilocalorie to Kilojoulekcal → kJEnergy Kilojoule to KilocaloriekJ → kcalEnergy

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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 reviewed: September 2026. Energy. Source basis: BIPM SI Brochure · NIST Guide to SI Appendix B.

Common questions

What is the factor for Joule to Kilocalorie?

1 J = 0.000239005736 kcal

Which formula does Joule to Kilocalorie use?

1 J = 0.000239005736 kcal. Joule is the base unit of the family, so the value is converted directly.

What is the most common mistake?

Food calories are kilocalories. Utility bills use kilowatt-hours. Both are energy units, but in different contexts.

When should I verify the result?

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