Convert

Watt-hour to Kilowatt-hour

Exact answer: 1 Wh = 0.001 kWh (exact – SI decimal prefix)

Watt-hour and Kilowatt-hour both belong to the Energy family. The difference is a decimal prefix, so the factor is a clean power of ten. Energy appears in electricity tariffs, food labels, heating costs and technical datasheets.

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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?

From100 Wh

Result0.1 kWh

Factor1 Wh = 0.001 kWh

Source basisBIPM SI Brochure · NIST Guide to SI Appendix B

Examples

01100 Wh = 0.1 kWh

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 Wh = 3600 J. Then the value is converted through the base unit J into Kilowatt-hour.

Table

Watt-hour to Kilowatt-hour
Watt-hour	Kilowatt-hour
100	0.1
500	0.5
1,000	1
2,000	2
5,000	5
10,000	10

Formula

1 Wh = 3600 J. Then the value is converted through the base unit J into Kilowatt-hour.

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 British thermal unit to Kilowatt-hourBTU → kWhEnergy Kilowatt-hour to KilocaloriekWh → kcalEnergy

Search and practice paths

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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 Watt-hour to Kilowatt-hour?

1 Wh = 0.001 kWh

Which formula does Watt-hour to Kilowatt-hour use?

1 Wh = 3600 J. Then the value is converted through the base unit J into Kilowatt-hour.

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.