GoKawiilThe easiest way to determine when any MacBook should be replaced is when it's no longer eligible for OS updates. Every year when Apple releases a major macOS version, the hardware in some older laptops is too weak to support the upgrade or work with modern security features. In many cases, the MacBooks left behind are simply too old, as it's not feasible for any company to test every OS update on hundreds of machines.
Looking at historical trends provides a good idea of what to expect for today's MacBooks. macOS 27 Golden Gate, expected to arrive in fall 2026, is compatible with all Macs running Apple silicon chips. The oldest of these are the M1 MacBook Air and M1 MacBook Pro, released in 2020. In addition to the latest macOS release, Apple currently supports the prior two releases with security patches. At present, macOS 14 Sonoma is the oldest supported version, and the oldest MacBooks that Sonoma works with are 2018 models.
From this, we can estimate roughly eight years of first-party software life from most MacBooks: six years getting the latest macOS release, plus an additional two years of security patches. After that, your laptop is still usable, but it's on an unsupported operating system that may warrant upgrading. Depending on what programs you use, third-party app compatibility can become an issue once your MacBook is no longer supported. For instance, Photoshop won't run on anything older than macOS 14, which is the oldest version Apple currently supports.