How many ounces in 1 teaspoon of dry ingredients?

Unfortunately this is not easy, because one is volume and the other weigh - so it matters what substance (how dense it is). An approximate ESTIMATE would be - 3 - 4 TABLESPOONS to an ounce - so about 9 to 12 teaspoons. With more dense/finely ground things being at the lower end and less dense/non packed things being at the higher end.

Better to weigh rather than measure!