A modem or router-modem combination unit typically uses 2-20 Watts with an average of 6 but for the sake of projecting power costs let’s go with 10 Watts just in case. By comparison your laptop uses 50 Watts and a refrigerator uses 200. Some people unplug the power supply for the modem when it’s not in use to conserve energy but many others prefer 24-hour internet access and leave it plugged in.

Average energy costs can fluctuate based on supply and demand. Prices tend to go up when and where demand increases. Energy pricing and sources are another topic so let’s use ballpark costs with the understanding that is a moving target.

In the U.S. the average cost of electricity is 13 cents per kilowatt hour (KWh) but the average includes a broad range of differences. It’s twice that cost in Alaska and three times that amount in Hawaii. Depending on where you live you can use the average or add to it for your estimate of how much running a router or router-modem costs.

If your power consumption is 10 Watts (likely it’s less but let’s go with 10 because we’re budgeting) and the router-modem is plugged in 24 hours a day at 13 cents average per kilowatt hour then your electricity cost is .03 cent per day. It would be .95 cents a month (still under $1) and $11.40 per year. Double the numbers for Alaska and triple for Hawaii. Even so, it’s still a relatively small amount.

Asking what any appliance costs to run is a great question today because leaving everything plugged in all the time has a cost and it’s not always necessary. We just forget. Don’t unplug your refrigerator overnight of course but do take a small step by walking around your home and seeing what does and doesn’t need to be “always on.” Small savings can add up.