Gigawatt-hour [GWh] to Milliwatt-hour [mWh] Converter

Quick Reference

1 Gigawatt-hour (GWh) = 1.0000e+12 Milliwatt-hour (mWh)

1 Milliwatt-hour (mWh) = 1.0000e-12 Gigawatt-hour (GWh)

How to Convert Gigawatt-hour to Milliwatt-hour

1 GWh = 1000000000000 mWh
1 mWh = 1e-12 GWh

To convert Gigawatt-hour to Milliwatt-hour, multiply the value by 1.0000e+12. To convert Milliwatt-hour back to Gigawatt-hour, divide by 1.0000e+12.

Example: convert 10 GWh to mWh:
10 GWh = 10 x 1000000000000 = 10000000000000 mWh

↔ Convert Milliwatt-hour to Gigawatt-hour

Gigawatt-hour

Definition: A gigawatt-hour (symbol GWh) is a unit of energy equal to one gigawatt (1,000,000,000 watts) of power sustained for one hour. It represents a very large amount of energy.

History/origin: The gigawatt-hour is a derivative of the watt-hour, using the SI prefix 'giga-' to denote a factor of one billion. It became relevant with the development of very large-scale power generation facilities.

Current use: Gigawatt-hours are used to measure the energy output of entire power grids, the energy consumption of large countries or regions, and the total energy production of large renewable energy projects.

Milliwatt-hour

Definition: A milliwatt-hour (symbol mWh) is a unit of energy equal to one-thousandth of a watt-hour. It represents a very small amount of energy.

History/origin: The milliwatt-hour is a derivative of the watt-hour, using the SI prefix 'milli-' to denote a factor of one-thousandth.

Current use: Milliwatt-hours are used in applications involving low-power electronics, such as sensors, small batteries, and medical devices.

Gigawatt-hour to Milliwatt-hour Conversion Table

Gigawatt-hour [GWh]	Milliwatt-hour [mWh]
1 GWh	1000000000000 mWh
2 GWh	2000000000000 mWh
5 GWh	5000000000000 mWh
10 GWh	10000000000000 mWh
20 GWh	20000000000000 mWh
50 GWh	50000000000000 mWh
100 GWh	100000000000000 mWh
200 GWh	200000000000000 mWh
500 GWh	500000000000000 mWh
1000 GWh	1000000000000000 mWh

Common pairs of Energy

Watt-hour

Watt-hour to Milliwatt-hour Watt-hour to Kilowatt-hour Watt-hour to Megawatt-hour Watt-hour to Gigawatt-hour Watt-hour to Joule

Milliwatt-hour

Milliwatt-hour to Watt-hour Milliwatt-hour to Kilowatt-hour Milliwatt-hour to Megawatt-hour Milliwatt-hour to Gigawatt-hour Milliwatt-hour to Joule

Kilowatt-hour

Kilowatt-hour to Watt-hour Kilowatt-hour to Milliwatt-hour Kilowatt-hour to Megawatt-hour Kilowatt-hour to Gigawatt-hour Kilowatt-hour to Joule

Megawatt-hour

Megawatt-hour to Watt-hour Megawatt-hour to Milliwatt-hour Megawatt-hour to Kilowatt-hour Megawatt-hour to Gigawatt-hour Megawatt-hour to Joule

Gigawatt-hour

Gigawatt-hour to Watt-hour Gigawatt-hour to Milliwatt-hour Gigawatt-hour to Kilowatt-hour Gigawatt-hour to Megawatt-hour Gigawatt-hour to Joule

Joule

Joule to Watt-hour Joule to Milliwatt-hour Joule to Kilowatt-hour Joule to Megawatt-hour Joule to Gigawatt-hour

Kilojoule

Kilojoule to Watt-hour Kilojoule to Milliwatt-hour Kilojoule to Kilowatt-hour Kilojoule to Megawatt-hour Kilojoule to Gigawatt-hour

Gigawatt-hour [GWh] to Milliwatt-hour [mWh] Converter

To convert Gigawatt-hour to Milliwatt-hour, enter your value in the GWh field above and the result in mWh will appear instantly. You can also use the conversion factor shown in the table on this page to calculate manually. The formula is always the same: multiply your GWh value by the fixed conversion ratio to get the equivalent in mWh.

Our Gigawatt-hour to Milliwatt-hour converter uses standardized conversion factors defined by international scientific and metrological organizations. All calculations are performed with full floating-point precision. You can also choose how many decimal places to display in the result, so you get exactly the level of detail you need.

Yes, absolutely. Simply swap the source and destination units in the converter — select mWh as your input unit and GWh as your output unit. The same precision and standardized conversion factor applies in both directions.

Converting between Gigawatt-hour and Milliwatt-hour comes up regularly in engineering, scientific research, construction, and everyday tasks that involve measurements from different unit systems. Our converter eliminates the risk of manual calculation errors and saves time whenever you need to switch between these two units.

Yes, the Gigawatt-hour to Milliwatt-hour converter is completely free. No account or registration is required, and there are no usage limits. It works on any device — smartphones, tablets, and desktop computers — directly in your browser.

Gigawatt-hour and Milliwatt-hour are both units used to measure the same physical quantity, but they belong to different measurement systems or represent different scales. The mathematical relationship between them is fixed and constant, which is what makes accurate conversion possible. Scroll up to see the exact conversion factor, formula, and a reference table for common values.

Gigawatt-hour [GWh] to Milliwatt-hour [mWh] Converter

Quick Reference

1 Gigawatt-hour (GWh) = 1.0000e+12 Milliwatt-hour (mWh)

1 Milliwatt-hour (mWh) = 1.0000e-12 Gigawatt-hour (GWh)

How to Convert Gigawatt-hour to Milliwatt-hour

1 GWh = 1000000000000 mWh
1 mWh = 1e-12 GWh

To convert Gigawatt-hour to Milliwatt-hour, multiply the value by 1.0000e+12. To convert Milliwatt-hour back to Gigawatt-hour, divide by 1.0000e+12.

Example: convert 10 GWh to mWh:
10 GWh = 10 x 1000000000000 = 10000000000000 mWh

↔ Convert Milliwatt-hour to Gigawatt-hour

Gigawatt-hour

Definition: A gigawatt-hour (symbol GWh) is a unit of energy equal to one gigawatt (1,000,000,000 watts) of power sustained for one hour. It represents a very large amount of energy.

Milliwatt-hour

Definition: A milliwatt-hour (symbol mWh) is a unit of energy equal to one-thousandth of a watt-hour. It represents a very small amount of energy.

History/origin: The milliwatt-hour is a derivative of the watt-hour, using the SI prefix 'milli-' to denote a factor of one-thousandth.

Current use: Milliwatt-hours are used in applications involving low-power electronics, such as sensors, small batteries, and medical devices.

Gigawatt-hour to Milliwatt-hour Conversion Table

Gigawatt-hour [GWh]	Milliwatt-hour [mWh]
1 GWh	1000000000000 mWh
2 GWh	2000000000000 mWh
5 GWh	5000000000000 mWh
10 GWh	10000000000000 mWh
20 GWh	20000000000000 mWh
50 GWh	50000000000000 mWh
100 GWh	100000000000000 mWh
200 GWh	200000000000000 mWh
500 GWh	500000000000000 mWh
1000 GWh	1000000000000000 mWh

Common pairs of Energy

Watt-hour

Watt-hour to Milliwatt-hour Watt-hour to Kilowatt-hour Watt-hour to Megawatt-hour Watt-hour to Gigawatt-hour Watt-hour to Joule

Milliwatt-hour

Milliwatt-hour to Watt-hour Milliwatt-hour to Kilowatt-hour Milliwatt-hour to Megawatt-hour Milliwatt-hour to Gigawatt-hour Milliwatt-hour to Joule

Kilowatt-hour

Kilowatt-hour to Watt-hour Kilowatt-hour to Milliwatt-hour Kilowatt-hour to Megawatt-hour Kilowatt-hour to Gigawatt-hour Kilowatt-hour to Joule

Megawatt-hour

Megawatt-hour to Watt-hour Megawatt-hour to Milliwatt-hour Megawatt-hour to Kilowatt-hour Megawatt-hour to Gigawatt-hour Megawatt-hour to Joule

Gigawatt-hour

Gigawatt-hour to Watt-hour Gigawatt-hour to Milliwatt-hour Gigawatt-hour to Kilowatt-hour Gigawatt-hour to Megawatt-hour Gigawatt-hour to Joule

Joule

Joule to Watt-hour Joule to Milliwatt-hour Joule to Kilowatt-hour Joule to Megawatt-hour Joule to Gigawatt-hour

Kilojoule

Kilojoule to Watt-hour Kilojoule to Milliwatt-hour Kilojoule to Kilowatt-hour Kilojoule to Megawatt-hour Kilojoule to Gigawatt-hour