How to check PostgreSQL database size

This returns raw bytes for calculations and a human-readable value for display.

SELECT
  current_database() AS database_name,
  pg_database_size(current_database()) AS size_bytes,
  pg_size_pretty(pg_database_size(current_database())) AS size_pretty;

pg_total_relation_size includes the relation, its indexes, and TOAST data. The catalog filter omits PostgreSQL system schemas.

SELECT
  n.nspname AS schema_name,
  c.relname AS relation_name,
  pg_total_relation_size(c.oid) AS total_bytes,
  pg_size_pretty(pg_total_relation_size(c.oid)) AS total_size
FROM pg_class AS c
JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE c.relkind IN ('r', 'm')
  AND n.nspname NOT IN ('pg_catalog', 'information_schema')
  AND n.nspname !~ '^pg_toast'
ORDER BY total_bytes DESC
LIMIT 25;

Logical database size does not necessarily include WAL, provider system files, backups, history storage, object storage, or provisioned disk headroom. Supabase explicitly distinguishes database size from disk size; Neon storage and billing categories also have provider-specific definitions.

• Sizes can change while a busy database is being measured.
• Catalog visibility and size-function permissions depend on the role and PostgreSQL version.
• Do not run broad diagnostics more frequently than needed on production systems.
• Use the same query and unit when comparing observations over time.