Time Machine backup drive doesn't have enough room to back up to My MacBook Pro has a 1 TB drive with 750 GB used. I keep receiving a message from Time Machine saying I don't have enough room to backup and to remove files. The Time Machine disk is 1 TB as well and I'm at a loss to see what to do.
Time Machine stores multiple versions of file which change over time so if the backup drive has the same size as the source drive this situation does happen after some time (it also may happen if the backup drive is bigger but much more seldomly). At this point you have two options


swap your backup drive for a bigger one and start a new backup on that
accept the fact that older versions of your backup will get deleted by Time Machine