Where to find power usage information on your PC

Your PC tracks how much power it is using right now, and Windows and Mac both let you see that data without installing anything extra. On Windows 10 and 11, the Task Manager shows real-time power draw for individual programs. On Mac, Activity Monitor does the same thing. Neither tool tells you your total electricity bill — that depends on your local power rates — but both show you which programs are draining the most energy and how hard your processor and graphics card are working at any moment.

The fastest way to open these tools is to search for them by name. On Windows, press the Windows key and type "Task Manager," then press Enter. On Mac, press Command+Space, type "Activity Monitor," and press Enter. Both open in seconds and start showing data when ready.

Key Takeaways

  • Windows Task Manager and Mac Activity Monitor both show power usage in real time without requiring any downloads or setup.
  • Task Manager's Power column shows which programs are using the most energy, measured as a percentage of your system's capacity.
  • Activity Monitor's Energy Impact column ranks programs by how much they drain your battery or power supply.
  • Closing or updating programs that show high power usage can reduce your electricity costs and extend battery life on laptops.
  • Your PC's power supply specifications tell you the maximum watts it can draw, but actual usage is usually much lower during normal work.

Checking power usage in Windows Task Manager

Open Task Manager by pressing Ctrl+Shift+Esc or by right-clicking the taskbar and selecting "Task Manager." Click the "Processes" tab if it is not already selected. Look for a column labeled "Power" — if you do not see it, right-click any column header and select "Power" to add it to the display.

The Power column shows a percentage rather than watts. A program showing 5% is using about 5% of your system's total power capacity at that moment. Programs at the top of the list are using the most energy. If you see a program you do not recognize using high power, you can right-click it and select "End task" to close it when ready. Task Manager will continue running and showing updated numbers as programs open and close.

Windows also shows an "Efficiency" column in some versions, which ranks programs as "High," "Normal," or "Low" based on how well they use power. A program marked "Low" efficiency is wasting energy relative to what it accomplishes. Closing or updating these programs first will have the biggest impact on your power bill.

Checking power usage on Mac with Activity Monitor

Open Activity Monitor by pressing Command+Space, typing "Activity Monitor," and pressing Enter. Click the "Energy" tab at the top of the window. You will see a list of all running programs with an "Energy Impact" column showing a number — higher numbers mean more power drain.

Unlike Windows, Mac does not show a percentage. Instead, Activity Monitor ranks programs relative to each other. A program at the top of the Energy Impact list is using significantly more power than one at the bottom. The number itself is less important than the ranking — if you see a program you do not use taking up the top spot, closing it will reduce power draw.

Mac also shows an "Avg Energy Impact" column, which averages power usage over the last 12 hours. This is useful for spotting programs that drain power even when you are not actively using them. A program with high Avg Energy Impact but low current Energy Impact is probably running background tasks. Quitting it or adjusting its settings may lower your overall power consumption.

Understanding your PC's power supply specifications

Your PC's power supply has a maximum wattage printed on its label — typically 500W, 650W, 750W, or higher for desktop computers. This is the most power your system can draw at once, not what it normally uses. During everyday work like browsing, email, and document editing, your PC uses far less — often 50 to 150 watts depending on your hardware.

You can find your power supply wattage by opening your PC case and looking at the label on the power supply unit itself, or by checking your PC's original documentation or manufacturer website. Laptops do not have user-replaceable power supplies, but you can find the wattage on the power adapter brick — it is usually printed as "65W," "100W," or similar.

Knowing your maximum wattage helps you understand whether a program using 10% power is actually a concern. On a 650W system, 10% is about 65 watts, which is normal for web browsing or light work. On a 300W laptop power adapter, 10% is only 30 watts. Task Manager and Activity Monitor do the math for you, so you do not need to calculate it yourself — just look at the ranking to see which programs are the biggest power users.

Programs that commonly use high power

Video games, video editing software, and 3D rendering programs use the most power because they push your graphics card and processor to their limits. Web browsers with many tabs open also use significant power, especially if those tabs contain video or auto-playing content. Cryptocurrency mining software, if installed, will show extremely high power usage.

Background programs you may not notice can also drain power. Windows Update, antivirus scans, indexing services, and cloud sync programs like OneDrive or Google Drive often run in the background. These are usually necessary, but you can see exactly how much power they are using and decide whether to pause them during battery-critical times on a laptop.

If a program shows high power usage and you do not recognize it, search the program name online before closing it. Some legitimate system programs have unfamiliar names. If you confirm it is unwanted, you can uninstall it through Settings > Apps on Windows or Applications folder on Mac.

Reducing power usage on your PC

The simplest step is to close programs you are not using. Every program you close frees up power for other tasks. If you see a program in Task Manager or Activity Monitor that you do not recognize, close it and see whether your PC runs better or worse. If nothing changes, it was probably safe to close.

Lowering your screen brightness saves significant power, especially on laptops. On Windows, press Windows+A to open Quick Settings and drag the brightness slider down. On Mac, click the Control Center icon in the top right and adjust brightness. A dimmer screen uses 10 to 20% less power while still remaining readable for most work.

Updating your programs and operating system can improve power efficiency. Developers often release updates that reduce power consumption by optimizing how programs use your processor and graphics card. Check for updates in Settings on Windows or System Settings on Mac.

If you use a laptop, switching to Battery Saver mode (Windows) or Low Power Mode (Mac) reduces power draw by limiting background activity and processor speed. Your PC will feel slightly slower, but battery life extends significantly. You can turn this mode on and off as needed depending on whether you are near a power outlet.

Monitoring power usage over time

Task Manager and Activity Monitor show power usage at the moment you open them, but they do not save historical data. If you want to track power usage over days or weeks, you can take screenshots of the Power column at the same time each day and compare them. This helps you spot whether a particular program is consistently draining power or whether power usage changes with your habits.

For more detailed historical tracking, third-party tools like HWiNFO on Windows or Macs Fan Control on Mac can log power data to a file over time. These tools are optional — Task Manager and Activity Monitor are sufficient for most people who just want to see which programs are using power right now.

If you are concerned about your electricity bill, the most useful approach is to check Task Manager or Activity Monitor once a week and close any programs that show unexpectedly high power usage. Over time, this habit will train you to notice which of your regular activities use the most power.

Frequently Asked Questions

Does Task Manager show my total electricity bill?

No. Task Manager shows power usage as a percentage of your system's capacity, not your actual electricity cost. To estimate your bill, you would need to know your local power rate (usually shown on your electric bill in dollars per kilowatt-hour) and multiply it by your PC's average wattage. Task Manager helps you reduce power usage, but it does not calculate cost directly.

Why does my power usage spike when I open a web browser?

Web browsers use power to render web pages, play videos, and run JavaScript code. Pages with auto-playing video or animations use significantly more power than text-only pages. Closing unused tabs and disabling auto-play in your browser settings will reduce power draw. Some browsers like Firefox and Safari are more power-efficient than others, so switching browsers may help if power usage is a concern.

Is it safe to close programs showing high power usage?

It depends on the program. Closing a game or web browser is always safe. Closing system programs like Windows Update, antivirus software, or cloud sync services is not recommended because they protect your PC or back up your files. If you are unsure whether a program is safe to close, search its name online or ask in a PC support forum before closing it.

Can I reduce power usage without closing programs?

Yes. Lowering screen brightness, enabling Battery Saver or Low Power Mode, closing unused browser tabs, and updating your software all reduce power usage without closing programs entirely. Disabling background app refresh in Settings (Windows) or System Settings (Mac) also helps. These changes are less dramatic than closing programs, but they add up over time.

What if Task Manager shows 0% power for all programs?

This usually means your PC is idle and not doing much work. It is normal and not a sign of a problem. Power usage will increase when you open programs or use your PC actively. If you see 0% even while running a game or video, the Power column may not be displaying correctly — try closing and reopening Task Manager.