Gigawatts and megawatts
A gigawatt is 1,000 megawatts. Nuclear reactors, large power plants and national grids are measured in gigawatts.
A megawatt is 1,000,000 watts. Wind turbines, data centers and small power stations are rated in megawatts.
Worked example
Convert 1.2 GW: 1.2 × 1,000 = 1,200, so 1.2 gigawatts is 1,200 megawatts. Likewise 2 GW = 2,000 MW.
Estimating in your head
The factor is a power of ten, so just move the decimal point 3 places to the right: 1.2 GW = 1,200 MW.
Going the other way
To convert megawatts to gigawatts, divide by 1,000 (or multiply by 0.001).
How this works
MW = GW × 1,000
1 GW = 1,000,000,000 W and 1 MW = 1,000,000 W, both by definition, so the factor is their ratio: 1,000 exactly. Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.
Frequently asked
How many megawatts are in a gigawatt?
1 gigawatt = 1,000 megawatts, exactly. The value follows from the unit definitions, so it never changes.
How do I convert gigawatts to megawatts?
Multiply by 1,000. For example, 2 GW × 1,000 = 2,000 MW.
What is 10 GW in megawatts?
10 GW = 10,000 MW. The table next to the converter lists more common values.
Is the result rounded?
Only on screen. The page computes with the exact definitions and removes floating-point noise past 15 significant digits; pick 3 to 12 significant figures, or use Copy result for the full value.
Sources
- NIST SP 811 Appendix B.8 — Factors for units listed alphabetically
- NIST SP 811 Appendix B.9 — Factors for units listed by kind of quantity
- Wikipedia — Horsepower
Reviewed Oct 17, 2026 · test vectors fixtures/units/power/gigawatts-to-megawatts/