Parameter value from (mb/gb) to bytes

Hi

Is there a simple way to dynamically get for example parameter „shared buffers“ value (megabytes or gigabytes) to bytes, for monitoring perspective..?

At the moment, this gives me value in GB.

# psql -U postgres -Atc "show shared_buffers;"

1GB

This value may as well be in MB. So I am looking a way to dynamically get the value in bytes.

Regards

Raul