Convert Power from Gigawatts to Milliwatts (GW to mW)

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Gigawatt to Milliwatt Conversion Formula

To convert from Gigawatt (GW) to Milliwatt (mW), use the following formula:

Milliwatt (mW)

= 109 × 1000× Gigawatt (GW)

= 1012× Gigawatt (GW)


Example

Let's convert 5 Gigawatt (GW) to Milliwatt (mW).

Using the formula:

5 × 1012 = 5000000000000

Therefore, 5 Gigawatt (GW) is equal to 5000000000000 Milliwatt (mW).

How many gigawatts are in one milliwatt? One Milliwatt (mW) contains 10-12 Gigawatts (GW) — the inverse of the factor above. Multiplying by 1012 takes you from gigawatts to milliwatts; multiplying by 10-12 brings you back.

Put in words: one gigawatt equals 1012 milliwatts, so the gigawatt is the larger unit of this pair. Converting between them never changes the amount of power being measured — only the size of the unit you count it in.

What is a Gigawatt (GW)?

A Gigawatt (GW) is a unit of power equal to one billion watts (109 W) or 1,000 megawatts.

It represents a significant amount of energy. To visualize this scale, a single gigawatt is roughly the amount of power generated by one large nuclear power plant.

This level of power is sufficient to supply electricity to hundreds of thousands of homes simultaneously.


How Are Gigawatts Used in Modern Energy?

The gigawatt is a standard unit for measuring the output of large-scale power generation facilities and national energy grids.

The capacity of major power sources is typically measured in gigawatts, including:

  • Hydroelectric dams
  • Large solar farms
  • Coal-fired power plants
  • Offshore wind farms

For example, a major offshore wind farm can have a generating capacity of over 1 GW, highlighting its importance in renewable energy planning and infrastructure development.


Why Is "1.21 Gigawatts" So Famous?

The term "gigawatt" gained widespread recognition through the classic 1985 film Back to the Future.

The iconic line "1.21 gigawatts!," delivered by Dr. Emmett Brown, refers to the immense power needed for the DeLorean time machine.

While often mispronounced as "jigowatt" in the movie, this famous quote introduced a massive audience to this unit of electrical power, cementing its place in popular culture.

What is a Milliwatt (mW)?

A milliwatt (mW) is a unit used to measure power.

It is equal to one-thousandth of a watt.

To put it simply, you need 1,000 milliwatts to equal one watt (1 W = 1,000 mW).


What Are Milliwatts Used For?

The milliwatt (mW) is the perfect unit for measuring the small amount of power used by many common electronic devices.

For example, the power of a Wi-Fi signal, the laser in a Blu-ray player, and the tiny LEDs on your electronics are all measured in milliwatts.

Using such small amounts of power is key to making the batteries last longer in your favorite gadgets, including wireless earbuds, smartwatches, and TV remotes.


How Do You Convert Milliwatts? (mW to Watts and dBm)

While the most common conversion is between milliwatts and watts (1,000 mW = 1 W), some technical fields use a different unit.

In telecommunications and fiber optics, power is often measured in dBm (decibels relative to one milliwatt). This scale makes it easier to work with a vast range of power levels.

For reference, 0 dBm is equal to exactly 1 mW.


Why Milliwatts (mW) Are Important for Laser Safety

When it comes to products with lasers, the milliwatt (mW) rating is a critical safety measure.

To prevent eye injuries, regulatory bodies like the FDA classify lasers based on their power output in milliwatts.

For example, handheld laser pointers sold to the public are legally required in most regions to have a power output of less than 5 mW.

This is a clear example of how milliwatt ratings are used to keep consumers safe.

Gigawatt to Milliwatt Conversion Table

Here are some quick reference conversions from Gigawatt (GW) to Milliwatt (mW):

GigawattsMilliwatts
0.000001 GW106 mW
0.001 GW109 mW
0.1 GW1011 mW
1 GW1012 mW
2 GW2000000000000 mW
3 GW3000000000000 mW
4 GW4000000000000 mW
5 GW5000000000000 mW
6 GW6000000000000 mW
7 GW7000000000000 mW
8 GW8000000000000 mW
9 GW9000000000000 mW
10 GW1013 mW
20 GW20000000000000 mW
30 GW30000000000000 mW
40 GW40000000000000 mW
50 GW50000000000000 mW
100 GW1014 mW
1000 GW1015 mW
10000 GW1016 mW