PostgreSQL: get table size (data & index & toast)

pg_get_table_sizes.sql

SELECT
  *,
  pg_size_pretty(table_bytes) AS table,
  pg_size_pretty(index_bytes) AS index,
  pg_size_pretty(total_bytes) AS total
FROM (
  SELECT
    *, total_bytes - index_bytes - COALESCE(toast_bytes, 0) AS table_bytes
  FROM (
    SELECT
      c.oid,
      nspname AS table_schema,
      relname AS table_name,
      c.reltuples AS row_estimate,
      pg_total_relation_size(c.oid) AS total_bytes,
      pg_indexes_size(c.oid) AS index_bytes,
      pg_total_relation_size(reltoastrelid) AS toast_bytes
    FROM
      pg_class c
      LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
    WHERE relkind = 'r'
  ) a
) a
WHERE table_schema = 'public'
ORDER BY total_bytes DESC;