Postgres Connection Sizing

Size max_connections safely by calculating work_mem saturation limits.

Optimal Active

32

Max Safe Limits

1365

Estimated Monthly Cost

AWS
$292.00
GCP
$332.88
AzureBest
$286.16
CPU: 8 coresRAM: 16.0 GB

Comprehensive Guide to Postgres Connection & Memory Limits

Understanding and correctly configuring PostgreSQL memory limits is critical for database performance and preventing out-of-memory (OOM) crashes in production. This calculator helps you optimally configure your `max_connections`, `shared_buffers`, and `work_mem` parameters to fully utilize your server's RAM without risking downtime.

Key PostgreSQL Memory Parameters

  • shared_buffers: Typically set to 25% of total system memory. This defines how much memory PostgreSQL uses for caching data pages.
  • max_connections: Every connection consumes a base amount of RAM (typically 2-10MB). Too many idle connections can drain memory rapidly; using a connection pooler like PgBouncer is often recommended.
  • work_mem: The memory used for internal sort operations and hash tables before writing to temporary disk files. Setting this too high with many active connections can quickly exhaust system memory.

Why Use This Calculator?

Accurate infrastructure sizing prevents unexpected cloud budget blowouts while guaranteeing SLA compliance and system reliability under peak traffic. By modeling your PostgreSQL memory profile before deployment, you can right-size your AWS RDS, Google Cloud SQL, or Azure Database for PostgreSQL instances, ensuring you aren't over-provisioning (wasting money) or under-provisioning (risking downtime).