How many watt hours are in a kilowatt hour?

Exactly 1,000. So 500 Wh is 0.5 kWh, 250 Wh is 0.25 kWh, 100 Wh is 0.1 kWh and 5,000 Wh is 5 kWh. The swap button between the two boxes runs it the other way, where 7.5 kWh is 7,500 Wh and 0.5 kWh is 500 Wh.

What is the formula for Wh to kWh?

Use kWh = Wh / 1,000 and Wh = kWh × 1,000. The exact power-of-ten factor yields a terminating decimal for finite decimal inputs, but long results can still round to twelve significant digits. Supplied 12,345 Wh is exactly 12.345 kWh and 0.5 Wh exactly 0.0005 kWh, both fitting the display. Wh to kJ also has an exact terminating factor, 3.6. BTU uses the separate stored rounded International Table coefficient of 1055.05585262 J; neither that coefficient nor a rounded display should be treated as an unrounded exact definition.

Is a kilowatt hour ever 1,024 watt hours?

No. The 1,024 step belongs to digital storage, where kibibytes and kilobytes disagree, and it has no equivalent in energy. Here kilo is the SI prefix and means a thousand exactly, in Wh, kWh and kJ alike. Digital storage is a separate category on this converter, reached from the strip of category buttons above the stage.

My battery is rated in mAh. Can this convert that?

mAh measures charge, with no menu entry here; charge alone does not establish energy. With a separately supplied constant voltage, ideal energy arithmetic is Wh = mAh × V / 1,000: a supplied 5,000 mAh at 3.7 V gives 18.5 Wh, and at 11.1 V gives 55.5 Wh. Those assumptions do not establish a battery’s usable energy, efficiency or actual voltage profile. Enter a supplied Wh quantity with Watt hour selected; 100 Wh is 0.1 kWh. A device or label type alone does not supply the missing assumptions.

What is the difference between watts and watt hours?

Watt measures power, a rate of energy transfer, while watt hour measures energy. For an explicitly supplied constant 60 W over exactly 2 h, separate arithmetic gives 60 × 2 = 120 Wh, which converts to 0.12 kWh. A nameplate rating and elapsed time do not establish actual variable consumption; that needs the power over the interval. Unit Converter only converts the supplied energy scalar and has no power-times-duration mode.

Worked example: what else is 1,000 Wh?

1 kWh, and the list restates the same energy as 3,600,000 joules, 3,600 kilojoules, 860,420.650096 calories, 860.420650096 kilocalories and 3,412.14163313 BTU. Half of that, 500 Wh, reads 0.5 kWh, 1,800,000 J, 1,800 kJ and 1,706.07081656 BTU. Each row has its own Copy button, and Copy result above the list copies the headline figure without separators.

How many joules is a watt hour?

Exactly 3,600 J: 1 W is 1 J/s and a fixed hour is 3,600 s. That is exactly 3.6 kJ per Wh. Using the exact thermochemical calorie of 4.184 J, 1 Wh displays as 860.420650096 cal or 0.860420650096 kcal. Show 1 more adds Electronvolt, defined here by exactly 1.602176634e-19 J per eV; 1 Wh displays as 2.24694326681e22 eV. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units. This focused page opens on Watt hour (Wh) to Kilowatt hour (kWh), while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account.

Will it tell me what a kilowatt hour costs?

No. This page converts the quantity of energy and carries no tariff, standing charge or region, since a rate per kWh changes by supplier and by month. It does the arithmetic that comes before that: read the watt hours off a label or a meter, convert to the unit the bill is written in, and apply your own rate.

Wh to kWh Converter

Kilo is the SI prefix for a thousand, so 1,000 Wh is exactly 1 kWh and the exact arithmetic shifts the decimal point three places left before twelve-significant-digit display rounding. 500 Wh is 0.5 kWh, 2,400 Wh is 2.4 kWh, 12,345 Wh is 12.345 kWh and 8 Wh is 0.008 kWh. The page opens with Watt hour in the From box and Kilowatt hour in the To box, ahead of whatever pair the converter last remembered, and the list under the headline carries the same energy in joules, kilojoules, calories, kilocalories and BTU, so 1,000 Wh also reads 3,600,000 J, 3,600 kJ and 3,412.14163313 BTU. Watt hours and watts are not the same quantity, and the converter handles only the first of them: a rating in watts is a rate, so multiply it by the hours it runs before bringing the figure here.

From

To0.001

Category: Energy

Base unit: joule

Uncommon units: Show 1 more

BTU uses the International Table definition (1,055.05585262 J); cal and kcal are thermochemical (4.184 J per cal). Wh and kWh are energy, not power in W or kW.

Results round to 12 significant digits using the listed unit definitions. Input must have a finite numeric magnitude and at most 512 significant digits. Type a single decimal or scientific number; a matching From unit suffix is accepted. Commas and grouped spaces separate thousands; decimal commas, fractions and compound measurements are refused.

1 Wh in every energy unit

JouleJ
3,600
KilojoulekJ
3.6
Caloriecal
860.420650096
Kilocaloriekcal
0.860420650096
Kilowatt hourkWh
0.001
British thermal unitBTU
3.41214163313

Selectable complete conversion

Unit Converter — Energy
Input: 1 (Watt hour, Wh)
Result: 0.001 kWh (Kilowatt hour)
Displayed values round to 12 significant digits.
BTU uses the International Table definition (1,055.05585262 J); cal and kcal are thermochemical (4.184 J per cal). Wh and kWh are energy, not power in W or kW.
All other units:
Joule (J): 3600
Kilojoule (kJ): 3.6
Calorie (cal): 860.420650096
Kilocalorie (kcal): 0.860420650096
Kilowatt hour (kWh): 0.001
British thermal unit (BTU): 3.41214163313
Electronvolt (eV): 2.24694326681e22

Common questions

How many watt hours are in a kilowatt hour?: Exactly 1,000. So 500 Wh is 0.5 kWh, 250 Wh is 0.25 kWh, 100 Wh is 0.1 kWh and 5,000 Wh is 5 kWh. The swap button between the two boxes runs it the other way, where 7.5 kWh is 7,500 Wh and 0.5 kWh is 500 Wh.
What is the formula for Wh to kWh?: Use kWh = Wh / 1,000 and Wh = kWh × 1,000. The exact power-of-ten factor yields a terminating decimal for finite decimal inputs, but long results can still round to twelve significant digits. Supplied 12,345 Wh is exactly 12.345 kWh and 0.5 Wh exactly 0.0005 kWh, both fitting the display. Wh to kJ also has an exact terminating factor, 3.6. BTU uses the separate stored rounded International Table coefficient of 1055.05585262 J; neither that coefficient nor a rounded display should be treated as an unrounded exact definition.
Is a kilowatt hour ever 1,024 watt hours?: No. The 1,024 step belongs to digital storage, where kibibytes and kilobytes disagree, and it has no equivalent in energy. Here kilo is the SI prefix and means a thousand exactly, in Wh, kWh and kJ alike. Digital storage is a separate category on this converter, reached from the strip of category buttons above the stage.
My battery is rated in mAh. Can this convert that?: mAh measures charge, with no menu entry here; charge alone does not establish energy. With a separately supplied constant voltage, ideal energy arithmetic is Wh = mAh × V / 1,000: a supplied 5,000 mAh at 3.7 V gives 18.5 Wh, and at 11.1 V gives 55.5 Wh. Those assumptions do not establish a battery’s usable energy, efficiency or actual voltage profile. Enter a supplied Wh quantity with Watt hour selected; 100 Wh is 0.1 kWh. A device or label type alone does not supply the missing assumptions.
What is the difference between watts and watt hours?: Watt measures power, a rate of energy transfer, while watt hour measures energy. For an explicitly supplied constant 60 W over exactly 2 h, separate arithmetic gives 60 × 2 = 120 Wh, which converts to 0.12 kWh. A nameplate rating and elapsed time do not establish actual variable consumption; that needs the power over the interval. Unit Converter only converts the supplied energy scalar and has no power-times-duration mode.
Worked example: what else is 1,000 Wh?: 1 kWh, and the list restates the same energy as 3,600,000 joules, 3,600 kilojoules, 860,420.650096 calories, 860.420650096 kilocalories and 3,412.14163313 BTU. Half of that, 500 Wh, reads 0.5 kWh, 1,800,000 J, 1,800 kJ and 1,706.07081656 BTU. Each row has its own Copy button, and Copy result above the list copies the headline figure without separators.
How many joules is a watt hour?: Exactly 3,600 J: 1 W is 1 J/s and a fixed hour is 3,600 s. That is exactly 3.6 kJ per Wh. Using the exact thermochemical calorie of 4.184 J, 1 Wh displays as 860.420650096 cal or 0.860420650096 kcal. Show 1 more adds Electronvolt, defined here by exactly 1.602176634e-19 J per eV; 1 Wh displays as 2.24694326681e22 eV. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units. This focused page opens on Watt hour (Wh) to Kilowatt hour (kWh), while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account.
Will it tell me what a kilowatt hour costs?: No. This page converts the quantity of energy and carries no tariff, standing charge or region, since a rate per kWh changes by supplier and by month. It does the arithmetic that comes before that: read the watt hours off a label or a meter, convert to the unit the bill is written in, and apply your own rate.

Results round to 12 significant digits using the listed unit conventions. Many factors are exact definitions; psi and parsec use rounded coefficients. Temperature includes scale offsets. Days and weeks are fixed-duration units, and unit conversion does not determine calendar dates, ambient pressure or a software label’s convention.