How to find the apps draining your MacBook battery
Three ways to see which apps use the most energy on a Mac, from Activity Monitor to the terminal, and what the numbers do not tell you.
When a MacBook that usually lasts all day is at 40% by lunch, one or two apps are usually behind it. macOS already measures this; the tools only differ in how easy the answer is to read.
1. The battery menu
Click the battery icon in the menu bar. Under “Using Significant Energy” macOS lists apps it considers heavy right now. The list is short and has no numbers, but it is the fastest check.
2. Activity Monitor
Open Activity Monitor and choose the Energy tab. Two columns matter:
- Energy Impact is the app’s use right now, on Apple’s own relative scale.
- 12 hr Power is the average over the last twelve hours, which catches an app that was heavy this morning and is idle now.
Sort by either column. Browsers and video calls usually lead, and a browser’s number is the sum of its tabs.
3. The terminal
The same measurement is available from top:
top -l 2 -s 2 -o power -stats pid,command,power -n 15It takes two samples two seconds apart and prints the second, sorted by power. The figure is relative, like Energy Impact, and it is listed per process: one app can appear as a dozen helper processes that you have to add up yourself.
What the numbers do not tell you
- They are shares, not watts. macOS reports each app’s relative use. It does not report how many watts an app draws.
- The screen is not an app. Display brightness, the radios and the system itself use a large part of the total, and no app list shows them.
- Quitting an app gives back less than its share. If an app holds 20% of the measured use, quitting it does not add 20% to your runtime, because the rest of the Mac keeps drawing power.
How Dotwatt shows it
Dotwatt reads the same power figure as top, groups helper processes under their app and keeps a running total for today and for the last 7 days. For the three heaviest apps it estimates the time you would gain by quitting, and marks it with ≈ because it is a rough estimate: the calculation assumes that about half of the Mac’s draw does not come from apps at all.
An app is flagged only when it holds a quarter of the use or more for two minutes, never while you are working in it, and never for the system itself.