Windows 11 doesn’t show how many watts your whole PC uses. It can show which apps use the most power: on a laptop, go to Settings > System > Power & battery > Battery usage. On any PC, open Task Manager and add the Power usage column. To measure the real wattage of a desktop or laptop, plug it into a plug-in watt meter (also called an electricity usage monitor).
Applies to: Windows 11 desktops and laptops. No downloads or administrator rights needed. Checked against Microsoft Support on September 29, 2026.
What Windows can and can’t tell you
| What you want to know | Where to look | What you get |
|---|---|---|
| Which apps drain a laptop battery | Settings > Power & battery > Battery usage | Each app’s share of battery use, in percent |
| Which apps use the most power right now | Task Manager > Processes > Power usage | A rating from Very low to Very high, not watts |
| How many watts your PC really uses | A plug-in watt meter between the wall and the PC | Real watts and total energy (kWh) |
| How to use less power | Settings > Power & battery | Power mode, Energy saver, and energy recommendations |
On a desktop PC, the Settings page is called Power instead of Power & battery, and there’s no Battery usage page, because there’s no battery to measure.
Method 1: See which apps use the most battery (laptops)
- Select Start > Settings > System > Power & battery.
- Select Battery usage.
- Choose Last 24 hours or Last 7 days from the list at the top. The graph shows how the battery level changed, and how long the screen was on, off, or asleep.
- Scroll to Battery usage per app. Use Sort by to order apps by Overall usage, In use, or Background.
How to read it:
- In use is battery used while you had the app open on screen.
- Background is battery used while the app ran without you looking at it. A high number here is worth fixing.
- For a fair picture, use the laptop on battery for at least an hour first. Right after startup, updates and syncing can make some apps look worse than they are.
If an app uses a lot in the background, select it in the list and choose Manage background productivity (or Manage background activity) to limit it, where the app offers that option. Microsoft suggests limiting background apps as one way to save power.
Method 2: Check power use per app in Task Manager
Task Manager rates how much power each running app uses right now. This works on desktops and laptops.
- Press Ctrl + Shift + Esc to open Task Manager, and select Processes.
- Right-click any column heading, such as Name or CPU.
- Select Power usage. Do it again and select Power usage trend.
- Select the Power usage heading to sort apps from highest to lowest.
Power usage shows the app’s impact right now. Power usage trend shows its impact over the last few minutes, so it’s better for spotting apps that are always busy. Both are ratings, not watts. An app rated High or Very high while you aren’t using it is a good one to close.
To close an app, select it and choose End task. Save your work in that app first, because unsaved changes are lost.
Method 3: Measure real watts with a plug-in meter
Windows can’t read how much power comes from the wall. For a real number, especially on a desktop, use a plug-in watt meter. They’re sold at hardware stores for about $20 to $40.
- Plug the meter into the wall outlet.
- Plug your PC’s power cord (or power strip with the PC and monitor) into the meter.
- Turn the PC on and let it sit at the desktop for a few minutes. Note the watts. This is your idle power.
- Do something demanding, like playing a game or exporting a video. Note the watts again. This is your load power.
- To see real-world use, switch the meter to its energy (kWh) mode and leave it for a full day or week.
A laptop measured this way also includes the power used to charge the battery. For a steady reading, measure it when the battery is full.
Estimate how much your PC costs to run
Once you know the watts, you can work out the cost:
- Divide the watts by 1,000 to get kilowatts. For example, 150 watts is 0.15 kW.
- Multiply by the hours you use it each day. 0.15 kW × 4 hours = 0.6 kWh a day.
- Multiply by 30 for a month: 0.6 × 30 = 18 kWh.
- Multiply by the price per kWh on your electric bill. At $0.17 per kWh, 18 kWh costs about $3.06 a month.
If you used the meter’s kWh mode, skip to step 4 with the kWh it measured.
Typical numbers vary a lot by hardware. As a rough guide, a laptop often uses somewhere around 15 to 60 watts, an everyday desktop about 50 to 150 watts, and a gaming PC can use several hundred watts under load. The processor and graphics card use the most power.
How to lower your PC’s power use
- Choose a more efficient power mode. Select Start > Settings > System > Power & battery (or Power). Next to Power mode, choose Best power efficiency. Microsoft says this cuts power use by limiting background activity. Switch back to Balanced or Best performance when you need more speed.
- Apply energy recommendations. On the same page, select Energy recommendations and apply the ones that suit you. Each one shows what it changes.
- Turn on Energy saver. On the same page, turn on Energy saver, or set it to turn on automatically when the battery gets low. You can also have it lower the screen brightness.
- Shorten screen and sleep timeouts. Open Screen, sleep, & hibernate timeouts and choose shorter times. Microsoft’s newer defaults turn the screen off after 5 minutes and sleep after 15 minutes when plugged in on many PCs.
- Lower the brightness, and use dark mode on OLED screens. The screen is one of the biggest power users on a laptop.
- Turn on Dynamic refresh rate, if your screen supports it: Settings > System > Display > Advanced display.
- Turn off startup apps you don’t need in Settings > Apps > Startup, so they don’t run in the background all day.
- Turn off Wi-Fi and Bluetooth from Quick Settings when you don’t need them.
If something doesn’t look right
- There’s no Battery usage page. You’re on a desktop, or Windows doesn’t see a battery. Use Task Manager and a plug-in meter instead.
- The Power usage column is missing. Right-click a column heading in Processes and select it. If it still doesn’t show, update Windows.
- The battery drops while the laptop is asleep. In Battery usage, compare the Sleep time with the battery graph. Unplug USB devices and docks before sleep, or use hibernate for long breaks.
- The meter reading keeps jumping. That’s normal. Power changes second by second as apps work. Use the kWh reading over a day for a better average.
- An app shows High even when closed. It may still be running in the background. Quit it from its icon near the clock, or turn it off in Startup.
Frequently asked questions
Can Windows 11 show my PC’s power use in watts?
No. Windows shows battery use by app and power ratings in Task Manager, but not total watts. For watts, use a plug-in meter.
Does a PC use power when it’s asleep or shut down?
Yes, but only a little. Sleep uses a small amount to keep your apps ready, and a shut-down PC can still draw a tiny bit while it’s plugged in. Hibernate and shut down use the least.
Will Best power efficiency slow my PC down?
It can make heavy tasks a little slower, because it limits background activity and performance. For everyday browsing and documents, most people won’t notice.
Is it cheaper to leave my PC on or turn it off?
Turning it off or letting it sleep uses less power than leaving it running. Setting a short sleep timeout gets you most of the savings without having to remember.
Does screen brightness really matter?
Yes. On laptops, the screen is one of the biggest power users, so lowering brightness can noticeably stretch battery life.
Next steps
To see how worn your laptop battery is, see how to check battery health in Windows 11. To change when the screen turns off, see how to change the screen timeout in Windows 11, and to stop apps working in the background, see how to turn off background apps in Windows 11. Microsoft’s guide is Power settings in Windows 11.
Related: How to limit battery charge to 80% on Windows 11.
Related: check PC performance in Windows 10.
Matt Jacobs has been working as an IT consultant for small businesses since receiving his Master’s degree in 2003. While he still does some consulting work, his primary focus now is on creating technology support content for SupportYourTech.com.
His work can be found on many websites and focuses on topics such as Microsoft Office, Apple devices, Android devices, Photoshop, and more.