Its not "how much" het the animal is. It is the chance or possibility that it IS het. It either is or it is not. Nick's helpful post shows you the possibility of the offspring being het in each scenario.
www.ASFRats.info African soft-furred rats information and exchange.
Also a 50%(or any %) het once proven (produced babies that are visible morph) are then considered 100%. Like stated previously the number shows possibilty of being a het(100%).
ok so if i was to breed my normal, i dont know what % he is, to a female albino, then the offspring would be 100% het because both are recessive right? and if i was to breed my normal to a spider than 50% would be het?
A normal is a normal. Hets come from selective breeding. Spiders are dominant so there is no het spiders. They either are or they are not. A spider to a normal gives you 50% chance per egg that you will get a spider.
An albino(visible) to a normal will produce all normals that are 100% het for albino. Breed that het to an albino and you will have 50% chance per egg for visible albinos(normals will be 100% hets). Albino to albino makes all albinos.