storage used by pg table

storage_used_by_pg_table.sql

SELECT *,
  pg_size_pretty(total_bytes) AS total,
  pg_size_pretty(index_bytes) AS index,
  pg_size_pretty(toast_bytes) AS toast,
  pg_size_pretty(table_bytes) AS table
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'
          AND relname = '<table-name>'
      ) a
  ) a;