Another way of showing the exact difference is 0.5 ounces is equal to 1 tablespoon in the US is 0.166666667 ounces is equal to 1 teaspoon in the US. Thus the difference between tablespoon and teaspoon is 0.333333333 ounces in the US. In the US, 1 teaspoon is equal to 1/3 tablespoon.