You open Activity Monitor because your MacBook battery is dropping faster than expected. You switch to the Energy tab and there it is — “Energy Impact.” A number beside each app. Some are small. Some are surprisingly high.
But what does it actually mean? Mac Energy Impact is not just CPU usage. It’s a broader measure of how demanding an app is on your system’s power resources at a given moment. And understanding it can change how you manage your Mac day to day.
What Energy Impact Measures
In Activity Monitor, the Energy Impact column estimates how much power an app is currently consuming relative to other running processes. It factors in:
- CPU activity
- GPU usage
- Disk activity
- Network usage
- Wake events
The number itself is relative, not absolute. It doesn’t represent watts or percentages. Instead, it shows how “expensive” a process is in terms of energy consumption compared to others.
You can find it here:
Applications > Utilities > Activity Monitor > Energy tab
The higher the number, the more strain that process is placing on battery life at that moment.
Energy Impact vs. 12-Hour Power
You’ll also notice another column: “12-hr Power.”
This shows a longer-term average. Some apps spike briefly — like exporting a video — but barely register across 12 hours. Others, like background sync services or browser tabs, may look small momentarily but accumulate steady impact over time.
That distinction matters.
A short spike isn’t usually the problem. Continuous background drain is.
Common Energy Drainers
Browsers are often near the top. Multiple open tabs, auto-playing videos, and extensions all increase energy impact.
Video conferencing apps also rank high because they use camera, microphone, network, and often GPU simultaneously. Cloud sync tools can quietly sit in the background and repeatedly wake the system. Spotlight indexing after a large file transfer can temporarily elevate system processes. You can sort by Energy Impact to see which apps are currently consuming the most resources.
Activity Monitor > Energy > Click “Energy Impact” column header
Optimizing Apps for Efficiency
Start simple. Close unused browser tabs. Disable auto-play features. Remove extensions you rarely use.
If an app constantly ranks high, check its settings. Some apps allow you to reduce background refresh, disable auto-sync, or limit hardware acceleration.
System Settings > General > Login Items
Remove apps that don’t need to launch automatically.
System Settings > Battery
Here you can enable Low Power Mode on MacBooks to reduce background activity and slightly dim the display.
On Apple silicon Macs, efficiency cores handle lighter tasks more gracefully than older Intel machines. But inefficient software can still push workloads onto performance cores, increasing consumption.
Background Activity and Wake Events
Some apps repeatedly wake your Mac from idle states to check for updates or sync data. These wake events contribute to Energy Impact even when you’re not actively using the app. You can identify frequent wake apps in the Energy tab by observing activity when your Mac should be idle.
If you notice something unusual, consider uninstalling or limiting permissions.
System Settings > Privacy & Security > Background App Refresh
Disable unnecessary background access.
Display and Energy Impact
Energy usage isn’t only about apps. Display brightness significantly affects battery drain.
System Settings > Displays
Reduce brightness manually or enable automatic adjustment.
Also consider:
System Settings > Battery > Options
Enable “Slightly dim the display on battery.”
Small adjustments here can reduce overall system load.
When High Energy Impact Is Normal
Some tasks are naturally demanding. Rendering video in Final Cut Pro. Compiling code in Xcode. Exporting large image batches.
These activities temporarily push Energy Impact higher. That’s expected. The key is whether the activity matches what you’re doing.
If your Mac is idle and an unknown process is consuming energy, that’s worth investigating.
Understanding Patterns Over Panic
Energy Impact isn’t a warning sign. It’s a visibility tool.
Your Mac is constantly balancing performance and efficiency. Apple silicon chips dynamically shift tasks between performance and efficiency cores to conserve energy when possible.
The metric helps you identify patterns. Is your battery draining because of one heavy app? Or ten small background ones? The goal isn’t to chase zero. It’s to stay aware.
Once you start checking Activity Monitor occasionally, you begin to recognize which apps behave responsibly and which ones don’t.
That awareness alone often leads to better battery life without drastic changes.
