Question: can you use tomato soup in place of tomato sauce?
Answer: For ¾ cup tomato sauce and 1 cup water, 2 cups of tomato ketchup can be used. Although not so commonly used, tomato soup serves as a great substitute. In fact, 1 can (10¾ oz) of tomato soup can substitute 1 cup of tomato sauce plus ¼ cup of water.