Up to 30 is a good number, but each case is different.
Cisco recommends no more than 25 clients per AP, type of traffic also matters, if the type of traffic is mostly emails, web browsing, etc ... then the value can go up to 35 clients per AP. If the type of traffic is video then the value is around 8 to 10 clients per AP.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.