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Free tool

MacBook battery life calculator

How long will your battery last? Pick your MacBook, your charge and what you're doing. The same 30% can be an hour or five, depending on the work.

What you're doing
Low Power Mode

Estimated time left

5h 10m

 

Low Power Mode would add about 1h 17m.

The same 54% on this Mac

  • Writing, notes, email8h 7m
  • Streaming video6h 19m
  • Web browsing5h 10m
  • Video calls2h 50m
  • Coding and builds1h 47m
  • Photo or video export1h 17m
  • Gaming1h 8m

These are typical figures. TurtleBar measures your own Mac and keeps this countdown in your menu bar, live.

How long does each percentage last?

Typical time left at each charge level, for a new battery at a comfortable brightness. At 30%, a 13-inch MacBook Air has about 2h 52m of browsing left, but only 1h 35m on video calls.

MacBook Air 13″ (M3), 52.6 Wh
BatteryWriting, notes, emailWeb browsingStreaming videoVideo callsCoding and builds
10%1h 30m57m1h 10m32m20m
20%3h1h 55m2h 20m1h 3m39m
25%3h 45m2h 23m2h 55m1h 19m49m
30%4h 31m2h 52m3h 30m1h 35m59m
40%6h 1m3h 50m4h 41m2h 6m1h 19m
50%7h 31m4h 47m5h 51m2h 38m1h 39m
60%9h 1m5h 44m7h 1m3h 9m1h 58m
70%10h 31m6h 42m8h 11m3h 41m2h 18m
80%12h 1m7h 39m9h 21m4h 12m2h 38m
90%13h 32m8h 36m10h 31m4h 44m2h 58m
100%15h 2m9h 34m11h 41m5h 16m3h 17m
MacBook Pro 14″ (M4, M4 Pro or M4 Max), 72.4 Wh
BatteryWriting, notes, emailWeb browsingStreaming videoVideo callsCoding and builds
10%1h 35m1h 1m1h 14m33m21m
20%3h 11m2h 2m2h 29m1h 7m42m
25%3h 59m2h 32m3h 6m1h 24m52m
30%4h 46m3h 2m3h 43m1h 40m1h 3m
40%6h 22m4h 3m4h 57m2h 14m1h 24m
50%7h 57m5h 4m6h 11m2h 47m1h 44m
60%9h 33m6h 5m7h 26m3h 20m2h 5m
70%11h 8m7h 5m8h 40m3h 54m2h 26m
80%12h 44m8h 6m9h 54m4h 27m2h 47m
90%14h 19m9h 7m11h 8m5h 1m3h 8m
100%15h 55m10h 8m12h 23m5h 34m3h 29m

How the estimate works

Energy left is your battery's rated capacity in watt-hours, times its health, times the charge. Time left is that energy divided by how many watts your Mac draws. A MacBook Air 13-inch draws around 3 to 6 W for light work and 20 W or more for exports and games; Pro models and larger displays draw more.

Your Mac, measured

Typical figures are a starting point. TurtleBar reads what your own Mac is drawing, learns your day hour by hour, and keeps the answer in the menu bar as a countdown. See also how to see battery time remaining on a Mac and make a charge last longer.

Questions

How long will 30% battery last on a MacBook?

On a MacBook Air 13-inch, 30% lasts about 2h 52m of web browsing, 4h 31m of writing, or 1h 35m on video calls. On a MacBook Pro 14-inch it is about 3h 2m of browsing. It depends far more on what you are doing than on the percentage.

How long does 20% battery last on a MacBook Air?

Roughly 1h 55m of web browsing, 2h 20m of streaming video, or 1h 3m on a video call on a 13-inch MacBook Air. Turning on Low Power Mode stretches the browsing figure to about 2h 23m.

How long will 50% battery last on a MacBook Pro?

On a 14-inch MacBook Pro, 50% is about 5h 4m of browsing, 2h 47m of video calls, or 1h 44m of coding and builds. The 16-inch model's 100 Wh battery lasts longer at the same percentage.

How do I see my Mac's battery time remaining?

macOS removed the time estimate from the menu bar in 2016. You can still get a one-off estimate by typing pmset -g batt in Terminal. TurtleBar keeps a live countdown in the menu bar, based on what your Mac is actually drawing.

How much longer does Low Power Mode make a MacBook last?

It varies with the workload. For everyday use, a saving of around 20% of power is a fair middle, which this calculator uses. It helps most on light and medium work, and is felt as a slower Mac on heavy work.

How accurate is this calculator?

It multiplies your battery's rated capacity by its health and charge, then divides by a typical power draw for that model and activity. Real draw varies with brightness, apps and background work, so treat the results as a good estimate. TurtleBar measures your own Mac instead of using typical figures.

Put this guide into practice

Know how long your Mac will last.

TurtleBar puts the time your Mac has left in the menu bar, tells you if it will last until your next deadline, and turns on Low Power Mode before you run out.

  • Time left, not a percentage
  • Automatic Low Power Mode
  • $4.99 once, 14-day refund

One-time purchase. No subscription. 14-day refund. macOS 13 Ventura or later, Apple Silicon and Intel.

TurtleBar popover showing the time left, Low Power Mode and a power chart