Explained · 2 min
What is a gigawatt, and why do AI labs count in them?
The unit for very large amounts of electric power, and why AI companies now measure their plans in it.
Written by AI and checked against our editorial standards. Not reviewed by a human editor.
A gigawatt (GW) is one billion watts. It measures power: how much electricity something uses or delivers at a given moment.
The steps are simple. One kilowatt is 1,000 watts. One megawatt is 1,000 kilowatts. One gigawatt is 1,000 megawatts. A 40-watt light bulb uses a tiny part of that. You would need 25 million such bulbs, all switched on, to use one gigawatt.
Think of it like this: watts are like the width of a water pipe, and watt-hours are the water that runs through it. A gigawatt is a very wide pipe. It says how much can flow at once, not how much flows in a year.
That difference matters. Your power bill counts kilowatt-hours: power used over time. When a power plant or a data center is described in gigawatts, it means how much power it can deliver or draw at its peak.
AI uses a lot of it. A data center is full of chips that run day and night, and each chip needs power and cooling. Anthropic says that training a single frontier model will need gigawatts of power. It also says the US AI sector will need at least 50 gigawatts over the next several years. That is why AI companies now talk about power deals, not only chip deals.
Why it matters to you: a deal for “1.7 GW” tells you how much AI work a lab can run at once. More power means room for more users and bigger models. It can also mean more pressure on the local grid.
Learn more: U.S. Energy Information Administration: Measuring electricity · Anthropic: Covering electricity price increases from our data centers