storage_space_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;