Changes from model to model and use-case to use-case.

Using the Laptop for heavy activities like Gaming, Video-Editing, 3D Modelling, App Development, will reduce battery life drastically.
Doing light tasks like Browsing, MS Office, Chatting, watching videos and so on, will give you higher (manufacturer advertised) battery life.

I will answer for the 13″ MacBook Pro with M1, for reference, since that’s the more popular model and also the newest 13″ version.
It can get around 12 hours of light use, as I said above, while it will fetch maybe 1–2 hours of heavy tasks.

Once again, keep in mind, varies with use, and model.
The 16″ model will get different numbers, the Air will get different, and if you vary workflow also, it will vary.