It really depends how you plan on steeping it.
For example, I tend to use the ratio 1 teaspoon per cup. One teaspoon is .167 ounces, meaning 24 teaspoons per 4oz. I tend to get about 2-3 infusions each teaspoon. If you infuse only twice, then about 48 cups, but if you steep 3 times each you can push that up to 72.
"In theory." Cinni said it best...
if my calculations are right.