Measured on a real homelab
On our homelab it uses about 89 MB of RAM on a normal hour, 128 MB in busy hours, and peaked at 867 MB over the last 30 days (3 users, household files and sync, with notify_push).
Per PHP process, not for the whole server; the built-in updater needs at least 256 MB.
Sources
RAM and CPU scale with concurrent user count (roughly 100 MB RAM per active user) and the number of enabled apps (e.g. Talk, Collabora).
Our rule of thumb: plan for the highest process memory recorded plus 25% headroom: 1.1 GB. Our workload is small — scale it with the factors above before buying hardware.
Combine it with other apps in the resource calculator →
Build it: Rent a VPS · Buy a mini-PC
Self-hosting photos, files or passwords? Keep an off-site copy (3-2-1 rule): pCloud lifetime backup
Memory per container from Netdata on the same server, summed across the whole stack (app, database and cache) hour by hour. The main figures are the processes' own memory (anonymous memory: heap, stacks). The docker stats figure is higher because it also counts active disk cache — which Linux gives back when it needs it — and shared memory such as PostgreSQL's shared buffers. Hours where the main container had no data are left out, not counted as zero. Re-measured with a script, not by hand.