Well, that depends entirely upon what you are measuring. Grams is a unit of mass and a teaspoon is a unit of volume. For instance: If you fill a teaspoon with water it's weight (mass x gravity) is very small. However, if you fill that same teaspoon with lead it would be much heavier. Seeing that gravity doesn't change, nor does the teaspoon...the only thing that changes is the mass (number of grams). So there isn't a set number of grams per teaspoon. It depends upon what you are measuring. This applies no mater how many Grams or teaspoons you are trying to convert.