That seems like such a simple question.
My recipes vary from 0.25% to 35% flavoring in the total mix. The ratio is completely dependent on the producer AND the specific flavoring.
If this was more like making KoolAid, there wouldn't be such an active sub-forum on the subject.
Care to share what flavoring, flavor and source? (Might be able to dial you in a bit more if it is not already in the sticky up top.)