Tablespace occupation

Hi,

On 11.2.0.4

I want to know how much data we have in each table space (in Gb) and size of each tablespace (in Gb).

I use :

select

  tablespace_name,

  USED_SPACE,

  round(used_percent,2)

from

  dba_tablespace_usage_metrics;

And we have:

NAME                 TYPE    VALUE

------------------------------------ ----------- ------------------------------

db_block_size            integer   8192

What should be my query to have the result in Gb?

Thanks.