Battery health
On macOS Ventura 13 or later, go to Apple menu > System Settings > Battery and click the info button next to Battery Health.
Cycle count
Hold the Option key, click the Apple menu and choose System Information. Under Hardware, select Power. The cycle count is listed under Battery Information.
Apple rates recent MacBook batteries, including the MacBook Air and MacBook Pro, to keep up to 80% of their original capacity at their maximum cycle count, which is 1,000 for recent models.
If you know your battery's design and current capacity, you can enter them in the checker's "Enter the numbers" option to get a grade.
Optimized Battery Charging
On macOS Big Sur 11 or later, the Mac learns your charging routine and can hold off charging past 80% when it expects to stay plugged in for a while, so the battery isn't held at full. "Charging On Hold" shows in the battery menu while it waits. If you need 100% now, choose Charge to Full Now.
Charge Limit
On Macs with Apple silicon running macOS Tahoe 26.4 or later, you can set a fixed charge limit anywhere from 80% to 100%. Charging stops near the limit and resumes if the charge drops more than 5% while plugged in. Find it in System Settings > Battery by clicking the info button next to Charging.
Your Mac will still charge to 100% now and then, so its battery estimates stay accurate.