DiagnoStack

JVM Heap Calculator

Most JVM tuning problems start with a heap size copied from a different project. Work out a starting -Xms/-Xmx from your actual RAM and workload type, with room left for what the JVM doesn't put on the heap.

If containerized, this is the container's memory limit — not the host's total RAM.
Adds container-aware flags so the JVM respects the container's memory limit rather than the host's.
Fill in the form and press Calculate.