How much is one ounce - 3 tablespoons?

1 ounce (oz) is equivalent to approximately 2 tablespoons (tbsp). So, one ounce minus 3 tablespoons is:

1 oz - 3 tbsp = 1 oz - 3 x 1/2 oz = 1 oz - 1.5 oz = -0.5 oz.

Therefore, one ounce minus 3 tablespoons is equal to -0.5 ounces.