MacBook Air battery life: how long it lasts and why

Apple's figures for each MacBook Air

These are Apple's figures from each model's tech specs page. "Video" is Apple TV app movie playback for the M1 to M3 models, and 1080p video streaming in Safari for M4 and M5.

Two things stand out. The ratings have stayed the same across six years of models. And the 15-inch models carry a battery about a quarter larger than the 13-inch, yet get the same rating, because the larger model draws more power. Apple's environmental reports show it: at idle with the display on, the 13-inch M5 draws 3.69 W and the 15-inch 4.11 W (at 115 V, from the MacBook Air M5 Product Environmental Report).

Not sure which you have? Apple menu › About This Mac shows the model and year.

How Apple tests, and what "up to" means

Each figure has a footnote. For the M5 models, Apple's reads: "Testing conducted by Apple in January 2026 using preproduction 13-inch MacBook Air systems with Apple M5, 10-core CPU, and 8-core GPU, and preproduction 15-inch MacBook Air systems with Apple M5, 10-core CPU, and 10-core GPU, all configured with 16GB of unified memory and 512GB SSD." In short:

• Wireless web: "browsing 25 popular websites while connected to Wi-Fi".
• Video: 1080p content in Safari over Wi-Fi on M4 and M5; "HD 1080p content" in the Apple TV app on M1 to M3.
• Screen: "display brightness set to 8 clicks from bottom", on every model. From M4 on, the keyboard backlight was off too.
• The caveat: "Battery life varies by use and configuration."

Those are light, steady tasks on a new battery with a moderate screen. To test yours the same way, press the brightness-down key until the screen is at its lowest, then press brightness-up eight times.

The figures also tell you what Apple's tests draw. Dividing battery size by hours: the 13-inch M5's 53.8 Wh over 15 hours of browsing is an average of about 3.6 W, and over 18 hours of video about 3.0 W. That's arithmetic on Apple's numbers, not a measurement, but it's a useful yardstick for the next section.

Why your MacBook Air may last less

Battery life is battery capacity divided by power draw, so anything that raises the draw shortens it:

• Brightness. Apple's advice is to "dim the screen to the lowest comfortable level to achieve maximum battery life" (Apple, Batteries: Maximizing Performance). Full brightness is well above Apple's test setting.
• Heavier work. Video calls, photo and video editing, compiling and games keep the chip busy for long stretches, at a much higher draw than Apple's tests. How many watts does a MacBook use? has the numbers we measured.
• Background apps. A browser with many tabs, sync clients and helpers keep working while you read. Activity Monitor's Energy tab shows which, and why is my MacBook battery draining so fast walks through finding them.
• Devices you charge from it. Apple's tip is to keep your MacBook "plugged in and powered on" when you use it to charge other devices; otherwise "those devices may drain the battery in your MacBook faster than normal". On our MacBook Pro, an iPhone charging from a USB-C port took 8.5 to 12.8 W.
• A worn battery. Apple designs the batteries in MacBook Air models from 2020 onward for 1,000 charge cycles, retaining "up to 80% of its original charge capacity" at that count (Apple, Determine battery cycle count). A battery at 85% Maximum Capacity holds 85% of the energy it did when new, so every figure above shrinks with it. How to check your MacBook's battery health shows where to look.
• Cold or heat. Apple says MacBooks work best at 10 to 35 °C (50 to 95 °F). In the cold, runtime drops for a while and recovers as the battery warms up; above 35 °C (95 °F), Apple warns, heat "can permanently damage battery capacity".
• The days after an update. Spotlight indexing and photo analysis run in the background after a big macOS update, and settle on their own.

Work out your own hours

You don't need to drain the battery to find out what it gives you. Use this:

Hours ≈ battery size (Wh) × Maximum Capacity ÷ average watts

For example, a 13-inch M5 MacBook Air whose battery is at 90% Maximum Capacity holds about 53.8 × 0.9 = 48.4 Wh. At 3.6 W, close to Apple's browsing test, that's about 13 hours. At 6 W it's about 8 hours, and at 10 W about 5. These are worked examples, not measurements of a MacBook Air.

• Battery size is in the table above.
• Maximum Capacity is in System Settings › Battery: click the info button next to Battery Health.
• Average watts is the one to measure on your own Mac, doing your own work. The watts guide shows how to read it in Terminal.

For a record of real days, System Settings › Battery shows the last 24 hours of battery level in 15-minute steps, and the last 10 days of energy use and screen-on time (Apple, Change Battery settings). A day where the line falls steeply is the one to look into.

How to make it last longer

1. Dim the screen to the lowest comfortable level.
2. Quit what you aren't using, starting with the top of Activity Monitor's Energy tab, and close heavy browser tabs.
3. Turn on Low Power Mode on battery in System Settings › Battery. It trades speed for runtime; what Low Power Mode does explains how.
4. Turn on Optimize video streaming while on battery (Battery › Options), which plays HDR video in standard dynamic range to use less energy.
5. Unplug accessories you aren't using, and charge your phone from the wall rather than the Mac while you're on battery.

None of these change how fast the battery wears. For that, macOS 26.4 and later can cap charging with Charge Limit; Should I use a charge limit? covers whether it's worth it.

How Tend helps

Tend shows your MacBook Air's whole draw in watts and each app's estimated share, so the "average watts" in the formula above is something you can read rather than guess, and the app costing you an hour sits at the top of the list. It also shows time remaining, battery health and cycle count. All of that is free, with 24 hours of energy history; Pro keeps 30 days.

Questions

Related guides

Sources

• Apple, tech specs: MacBook Air (M1, 2020), MacBook Air (M2, 2022), MacBook Air (15-inch, M2, 2023), 13-inch and 15-inch M3, 13-inch and 15-inch M4, 13-inch and 15-inch M5, and MacBook Air tech specs
• Apple, MacBook Air (M5) Product Environmental Report, March 2026
• Apple, Batteries: Maximizing Performance
• Apple, Determine battery cycle count for Mac laptops
• Apple, Change Battery settings on a Mac laptop
• USB-C power out read from ioreg -rn AppleSmartBattery on our MacBook Pro (M2 Max), macOS 27.0.1, 20 October 2026

Spotted something out of date? Tell us and we'll fix it.