How to check free space in tablespaces

Query shows tablespace usage and lists tablespace names including the database name:

select d.status,
 db.name dbname,
 d.tablespace_name tsname,
 d.extent_management,
 d.allocation_type,
 to_char(nvl(d.min_extlen / 1024, 0),
   '99G999G990D90', 'NLS_NUMERIC_CHARACTERS = '',.'' ')
   "ALLOC_SIZE (K)",
 d.contents "Type",
case
when(d.contents = 'TEMPORARY') then
 to_char(nvl(a.bytes / 1024 / 1024, 0),
 '99G999G990D90', 'NLS_NUMERIC_CHARACTERS = '',.'' ')
else
 to_char(nvl(t.bytes / 1024 / 1024, 0),
 '99G999G990D90', 'NLS_NUMERIC_CHARACTERS = '',.'' ')
end as "Size (M)",
 to_char(nvl((a.bytes - nvl(f.bytes, 0)) / 1024 / 1024,   0),
 '99G999G990D90', 'NLS_NUMERIC_CHARACTERS = '',.'' ')
 "Used (M)",
 to_char(nvl((a.bytes - nvl(f.bytes, 0)) / a.bytes * 100,   0),
 '990D90', 'NLS_NUMERIC_CHARACTERS = '',.'' ')
 "Used (%)"
from sys.dba_tablespaces d,
   (select tablespace_name,
    sum(bytes) bytes
  from dba_data_files
  group by tablespace_name)
a,
   (select tablespace_name,
    sum(bytes) bytes
  from dba_temp_files
  group by tablespace_name)
t,
   (select tablespace_name,
    sum(bytes) bytes
  from dba_free_space
  group by tablespace_name)
f,
 v$database db
where d.tablespace_name = a.tablespace_name(+)
and d.tablespace_name = f.tablespace_name(+)
and d.tablespace_name = t.tablespace_name(+)
order by 10 desc;