Mac battery health calculator

Find your MacBook battery's real capacity and cycle count, and what they mean.

1. Run this in Terminal

ioreg -rn AppleSmartBattery -w0 | grep -oE '"(DesignCapacity|NominalChargeCapacity|AppleRawMaxCapacity|CycleCount)" ?= ?[0-9]+' | sort -u

2. Paste what it prints

Design capacity (mAh)Full charge capacity (mAh)Cycle count

Paste the output, or type the numbers in, to see the battery’s health.

What the numbers mean

Design capacity is how much charge the battery held when new, in milliamp-hours.
Full charge capacity is how much it holds now. Batteries lose capacity as they age, mostly with use and heat.
Cycle count goes up by one each time you’ve used a full battery’s worth of charge, in any number of sessions.

Apple designs the batteries in most current MacBook models for 1,000 cycles, and to keep up to 80% of their original capacity when they get there. Older models were designed for 300 or 500; Apple’s support page lists every model.

Checking without Terminal

Open System Settings → Battery and click the ⓘ button next to Battery Health to see its condition and Maximum Capacity.
For the cycle count, hold Option, click the Apple menu, choose System Information, and select Power.

Updated 25 September 2026