You can measure the actual balance point like I believe everyone is talking about. However, your perceived forward or backend weight bias is going to be based on where you grip the cue.
I have a fairly long armspan and hold almost all cues near the back of the wrap or even on the sleeve for some shots. As a result, cues that feel neutrally balanced or forward balanced to me can feel too back heavy to someone else who grips the handle further forward.
In other words, the more cue behind your grip hand, the more rearward balanced the cue will feel and vice versa. Again, this is "perceived" weight bias or balance.