# How Much Energy Do Your Computer and Router Use?

Saving energy (and money) is always easier when you know how much you’re using. But because many of the convenient smaller appliances we use seem to draw little amounts of power, we all too often discount how their use really does impact our electricity bills. With our How Much Energy Does This Appliance Use? series, we’ll examine what’s watt in small appliances to see approximately how much they use. To help you understand very basic electrical consumption calculations, you’ll need to keep a simple equation in mind: Volts (V) x Amperes (I) = Watts (W). What you’ll discover is how just how small appliances can contribute to your home’s energy usage and how these little conveniences can make big differences on your bill.

At first glance, it might seem like your computer equipment is a major consumer of electricity. In most homes with internet access, the router is plugged in and running 24 hours a day. In some, the computer is always on, too. Throw in a device that needs frequent recharging like a tablet, and you start getting the idea that all these electronics are running up your electric bill. However, the truth is there’s a good chance the total energy consumption of your computers and router costs less per month than a premium cup of coffee, and maybe a lot less.

## How Much Electricity Does My Computer Use?

Laptop and desktop computers span a wide range of wattages, but the high end of that range — about 250 watts for high-performance desktops — is comparable to the top wattages of modern flat screen TVs. If you owned one of these high-performance devices and ran demanding processes on it day and night, it would still cost less than 50 cents per day at an electricity rate of ten cents per kWh.

Most desktop computers will consume far fewer watts than that, and laptop electric power consumption is even less. If you check the label on your laptop’s power adapter, you should see a wattage listed. Smaller laptops typically use 65-watt adapters, while larger ones may have 90-watt adapters. What’s more, the listed computer wattages represent the maximum levels, so the actual energy consumption of your laptop is likely to be lower than the number on the label. Even at the maximum, a large laptop drawing 90 watts for 12 hours would cost less than 11 cents per day at the ten cents per kWh rate.

## How Many Watts Does My Computer Use?

Understanding the true energy consumption of your computer is more complicated than checking the listed wattage, however. Computers draw different levels of electricity based on what they’re doing at the time. Playing a graphics-heavy game that pushes the processor to the limit uses more energy than checking your email.

There are a couple of ways to get a more accurate picture of your computer’s energy consumption. You can use software such as Microsoft’s free Joulemeter tool to analyze your system’s performance and estimate energy use. You can also use an electrical adapter that monitors energy consumption in real time.

## How Much Energy Do Routers Use?

There are some “always on” appliances that can make a real dent in your electric bill. Your refrigerator, for example, is likely adding at least a few dollars per month all on its own. But when it comes to your router, chances are you’re getting the magic of wireless internet for just pennies worth of electricity.

The typical wireless router wattage is around six, and the most demanding models only draw about 20. At ten cents per kWh, that six-watt router will use about a cent and a half’s worth of electricity per day, adding up to \$5.26 per year.

## How Much Energy Do Tablets Use?

While it doesn’t spend all day connected to your outlet, your favorite tablet surely makes frequent stops for a recharge — at least as often as every other day. But all that charging doesn’t add up to much.

The Electric Power Research Institute (EPRI) studied the electricity consumption of iPads and found that the typical user consumes less than 12 kWh of electricity in an entire year of recharging. That’s just \$1.20 for a customer with a ten cents per kWh rate.

## Don’t Sweat the Small Stuff

EPRI’s study also examined the energy consumption of laptop computers and found the annual average to be 72.3 kWh. At ten cents per kWh, that comes to \$7.23. Add that to the \$5.26 for a router and \$1.20 for a tablet and you come to a total of \$13.69 per year, or \$1.14 per month.

## Energy Saving Tips for Your Computer and Router

• If you’re shopping for a new computer, checking the current models that qualify for ENERGY STAR certification will help you avoid the more power hungry-machines.
• To save electricity with the computer you already own, try dimming the screen brightness and setting the system to hibernate automatically after a certain period of inactivity.

While it never hurts to use energy saving settings on these devices when you can, if you’re trying to make a major impact on your electricity bills there are far more impactful appliances to look toward than your computer equipment. Check out the rest of our series to learn about your other electronics.