Holiday Math, Checked Twice
How Many Christmas Lights Can a Nuclear Reactor Power?
37.6 Times Around the Earth
The U.S. Department of Energy ran this math with a generic set of LED mini lights and got about 27 laps around the planet. We ran the same math with a real set of lights we sell. One reactor goes a lot further.
Where This Started
In December 2025, the Office of Nuclear Energy published a holiday infographic with a question we could not stop thinking about: how many holiday lights could one nuclear reactor run?
Their answer was enough to wrap the Earth more than 27 times. For that math they used the high end for a set of LED mini lights: 7 watts for 100 lights on a 25-foot cord.
We wanted to know what happens with a set that is actually sitting on our shelves.
Credit where it's due: the idea and the original math come from the U.S. Department of Energy. Read their original infographic (opens in a new tab).
Our Math, Step by Step
1,000,000,000 Watts
A typical U.S. nuclear reactor produces about 1 gigawatt of power. That is a billion watts.
4.8 Watts per Set
One set of our 70-count 5mm warm white LED Christmas lights draws 4.8 watts and measures 23.7 feet end to end.
208,333,333 Sets
1,000,000,000 ÷ 4.8 = 208,333,333 sets. That is 14.6 billion LEDs and 4.94 billion feet of lights.
37.6 Laps
4,937,500,000 feet ÷ 5,280 = 935,133 miles. Divide by 24,900 miles around the equator and you get 37.6 times around the Earth.
One Reactor, One Very Bright Planet
Same reactor, same yardstick as the original infographic. The only thing we changed was the set of lights.
Why Our Lights Go Further
It's the spec sheet, not magic. The original math used 7 watts per set, the high end for mini lights. Our 70-count 5mm set is rated at 4.8 watts, about 0.069 watts per LED.
The 4-inch spacing does the rest. Per foot of lights, our set uses about 0.20 watts, compared with 0.28 watts in the original math. That's how the same reactor stretches from 27 laps to 37.6.
The Big Bulb Edition
Prefer big bulbs on your roofline? Our C9 ProCore® LED bulbs draw 0.84 watts each.
Spaced 12 inches apart on a stringer, one reactor could light 1.19 billion C9 bulbs. That is 225,469 miles of roofline, or 9.1 times around the Earth, in bulbs big enough to see from the street.
How Much Reactor Does Your Display Use?
Enter your display and we'll do the nuclear math. Wattages come from the two products above, so treat it as a friendly estimate.
Back Here on Earth, a Wall Outlet Will Do
You won't need a reactor for your display. Up to 45 of our 70-count 5mm warm white sets connect end to end and run from a single outlet. That is more than 1,000 feet of lights for about 216 watts.
Safety Notice
Caution: Do Not Plug Into a Nuclear Reactor
Our Christmas lights run on a standard 120-volt household outlet. Reactor not included, and no, we can't get you one.
Frequently Asked Questions
How many Christmas lights can one nuclear reactor power?
About 208 million sets of our 70-count 5mm warm white LED Christmas lights. Each set draws 4.8 watts, so one 1-gigawatt reactor could run roughly 14.6 billion LEDs and 935,133 miles of lights, enough to circle the Earth 37.6 times.
How much electricity does a set of LED Christmas lights use?
Our 70-count 5mm warm white LED set is rated at 4.8 watts, and our C9 ProCore® LED bulbs are rated at 0.84 watts per bulb. Every product page lists its wattage in the spec table.
How many LED Christmas light sets can I connect end to end?
Up to 45 sets of our 70-count 5mm warm white LED lights can run end to end from one outlet. The limit is different for each product, so check the spec table on the product page you are using.
Where did the nuclear reactor idea come from?
The U.S. Department of Energy's Office of Nuclear Energy asked the question first in a December 2025 infographic. They used a generic 7-watt set of LED mini lights and got about 27 trips around the Earth. We reran their math with the specs of a real set we sell.
Sources and How We Did the Math
- Original question and math: U.S. Department of Energy, Office of Nuclear Energy, "INFOGRAPHIC: How Many Holiday Lights Can a Nuclear Reactor Power?" (opens in a new tab), December 23, 2025.
- Reactor output: 1 gigawatt for a typical U.S. reactor, the same figure used in the original infographic.
- Light specs: wattage, length and end-to-end limits from our 70-count 5mm warm white set and C9 ProCore® bulb product pages.
- Earth: 24,900 miles around the equator, the same figure used in the original infographic. Moon: 238,855 miles, the average distance from the Earth.
This is a thought experiment for fun. It skips real-world details like transmission losses and a truly heroic number of extension cords. The Department of Energy did not review or endorse this page. We just liked their question.
