This blog suggests a pragmatic approach to calculate the required memory for java applications (i.e. load test) for a concrete load profile, or even it is not calculated at all but later, in production, changes to JVM parameters are applied as reaction to already experienced java memory problems.
Often the required java memory is calculated by applying some “guru-defined” ratio (e.g.”4GB per vCPU” or “4 GB memory per 1000 SAPS”) or is determined in experimental way (e.g.