How much Ram to allocate to Minecraft Server (for 5 simultaneous players)?

I have a server at home and would like to play with (5 simultaneous) friends on it. How much ram should I allocate to the server?

More about the server:

Minecraft version: Spigot-1.16.4

Plugins: Minepacks (similar to a safe where you can store your things)

Many always think they need more than 5GB or so, 512MB or so is enough… (at least I always use 512MB)

All right, I'll see if it works that well.