Convert 21 Megawatt (MW) to Gigawatt (GW).

21 Megawatt equals 0.021 Gigawatt. Multiply 21 by 0.001.

21 Megawatt = 0.021 Gigawatt

Worked example: converting Megawatt to Gigawatt

Step 1 — start with the formula. GW = MW × 0.001
Step 2 — substitute your figure. 21 MW × 0.001
Step 3 — read the result. 21 MW = 0.021 GW
Step 4 — check it in reverse. MW = GW × 1,000 returns 21 MW, which matches the figure you started with.

Power Converter

22 units available

Decimals:

From

To

0.021

21 MW = 0.021 GW

Formula:

GW = MW × 0.001

With your value: 21 MW = 0.021 GW

How big is that?

Everyday references on a logarithmic scale, all expressed in megawatt so you can sanity-check the result.

LED bulb (1/2.3e+6 your value)0.00000900 MW

Laptop (1/3.2e+5 your value)0.0000650 MW

Microwave oven (1/2.1e+4 your value)0.00100 MW

Electric kettle (1/7.0e+3 your value)0.00300 MW

Family car engine (1/2.3e+2 your value)0.0900 MW

Your value21.0 MW

Other Megawatt to Gigawatt conversions

15 MW to GW 16 MW to GW 18 MW to GW 20 MW to GW 24 MW to GW 25 MW to GW 26 MW to GW Full Megawatt to Gigawatt converter

Megawatt to Gigawatt Conversion Table

Megawatt (MW)	Gigawatt (GW)
0.5	0.0005
1	0.001
2	0.002
5	0.005
10	0.01
15	0.015
20	0.02
25	0.025
50	0.05
100	0.1
250	0.25
500	0.5
1000	1

Gigawatt to Megawatt Conversion Table

Gigawatt (GW)	Megawatt (MW)
0.5	500
1	1,000
2	2,000
5	5,000
10	10,000
15	15,000
20	20,000
25	25,000
50	50,000
100	100,000
250	250,000
500	500,000
1000	1,000,000

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Megawatt (MW)

Power

Exact conversion

Derived from the watt (1 W = 1 J/s).

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Gigawatt (GW)

Power

Exact conversion

Derived from the watt (1 W = 1 J/s).

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Megawatt to Gigawatt

To convert from Megawatt (MW) to Gigawatt (GW), multiply the value by 0.001.

Formula: GW = MW × 0.001

Reverse: MW = GW × 1,000

Step-by-Step Example

Start with your value in Megawatt. For example: 5 MW
Multiply by the conversion factor: 5 x 0.001
The result is: 0.005 GW

About Megawatt

The megawatt (MW) is a unit of power. One megawatt equals 1.000000 × 10^+6 watts. UnitConvertLab converts it against every other power unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: power calculations, engineering and science, education.

About Gigawatt

The gigawatt (GW) is a unit of power. One gigawatt equals 1.000000 × 10^+9 watts. UnitConvertLab converts it against every other power unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: power calculations, engineering and science, education.

Frequently Asked Questions

What is 21 Megawatt in Gigawatt?

21 Megawatt equals 0.021 Gigawatt.

How many Gigawatt are in 1 Megawatt?

There are exactly 0.001 Gigawatt in 1 Megawatt. This means the conversion factor from Megawatt to Gigawatt is 0.001.

What is the formula to convert Megawatt to Gigawatt?

The formula to convert Megawatt to Gigawatt is: GW = MW × 0.001. For example, to convert 10 Megawatt to Gigawatt, you would multiply 10 by 0.001.

What is a Megawatt?