PostgreSQL Config Calculator | Postgres Tuning

PostgreSQL config calculator: enter RAM, CPUs, storage and workload to get tuned postgresql.conf or ALTER SYSTEM settings for PostgreSQL 10 to 19. Free.

Also known as: postgresql config calculator · postgres tuning calculator · postgresql.conf generator · postgresql performance tuning calculator · postgres config generator · shared_buffers calculator · work_mem calculator · postgresql settings calculator · postgres memory configuration · tune postgresql.conf online

sql and database tools

devops and infrastructure tools

calculators

Server Details

PostgreSQL version

Operating system

Workload

Total RAM

CPUs (vCPUs)

Max connections

Data storage

Total data size

Enter what the PostgreSQL server itself has. On a shared host or a container with a memory limit, enter the memory PostgreSQL may use, not the whole machine.

Tuned Config Output

Warnings as comments

About PostgreSQL Config Calculator

PostgreSQL Config Calculator is used to pick starting values for postgresql.conf from a server's RAM, CPUs, storage and workload. A stock install assumes a tiny machine: 128MB of shared_buffers and 4MB of work_mem. The calculator sizes memory, WAL, planner costs, parallel workers and autovacuum for PostgreSQL 10 through 19 and explains each value, using the same formulas as the open-source PGTune project.

Key Features

Sizes shared_buffers, effective_cache_size, work_mem and maintenance_work_mem from RAM and the workload
Sets planner costs and I/O concurrency for NVMe, SSD, network block storage such as EBS, or HDD
Version aware: io_method and I/O workers for PostgreSQL 18 and 19, lz4 WAL compression on 15 to 18, and no setting a version lacks
Outputs postgresql.conf lines or ALTER SYSTEM statements, with restart-required settings marked
Warns when max_connections cannot fit in RAM, when huge pages are worth reserving, and when a setting can stop startup
Explains every value and links to its page in the PostgreSQL documentation for your version

Use Cases

Tune a fresh PostgreSQL 18 install on an EC2 instance in us-east-1 before it takes production traffic
Size work_mem for a Django or Rails app that runs 200 connections through PgBouncer
Check a data warehouse on 256GB of RAM before a nightly reporting job runs out of memory
Prepare ALTER SYSTEM statements for a server where you can run psql as a superuser but cannot edit files
Compare settings before and after moving a database from HDD to NVMe storage
Start a local development database on a MacBook without letting it take half the RAM

Supported Formats

postgresql.conf

ALTER SYSTEM (SQL)

PostgreSQL 10 to 19

Linux

Windows

macOS

Related Keywords

postgresql config calculator

postgres tuning calculator

postgresql.conf generator

postgresql performance tuning calculator

postgres config generator

shared_buffers calculator

work_mem calculator

postgresql settings calculator

postgres memory configuration

tune postgresql.conf online

How much RAM should shared_buffers get, and why not more?

About 25% of RAM is the usual starting point on a dedicated server, and the PostgreSQL documentation says more than 40% is unlikely to work better. PostgreSQL reads and writes through the operating system's own cache, so memory given to shared_buffers is memory the page cache no longer has, and hot data ends up cached twice. A larger shared_buffers also needs a larger max_wal_size to spread out checkpoint writes. The rest of RAM is not idle: effective_cache_size tells the planner how much the operating system is likely caching, and work_mem is spent per sort or hash, several times per query and per connection, which is why this calculator divides what is left after shared_buffers by connections times three. On Amazon RDS and Aurora the settings live in a DB parameter group you change from the console, the AWS CLI or the API; AWS documents ALTER DATABASE, ALTER ROLE and SET there, not ALTER SYSTEM, so enter these values in a custom parameter group.

Privacy & Security

All processing happens locally in your browser. Your data never leaves your computer, ensuring complete privacy and security.

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Frequently asked questions

What is PostgreSQL Config Calculator used for?

PostgreSQL config calculator: enter RAM, CPUs, storage and workload to get tuned postgresql.conf or ALTER SYSTEM settings for PostgreSQL 10 to 19. Free.

Is PostgreSQL Config Calculator free to use?

Yes. PostgreSQL Config Calculator is completely free with no usage limits, and there is no paid tier required to use it.

Do I need an account to use PostgreSQL Config Calculator?

No. PostgreSQL Config Calculator works immediately in your browser with no signup, login, or email address required.

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