The number of tomatoes needed to make one jar of fresh tomato sauce can vary depending on the size of the tomatoes, the desired consistency of the sauce, and the size of the jar. However, as a general guideline, you will typically need around 8 to 10 medium-sized tomatoes to make approximately one quart (32 ounces) of tomato sauce.
Keep in mind that this is just an estimate, and the actual quantity may vary depending on factors such as the juiciness of the tomatoes and how much you cook the sauce to reduce it. It's always a good idea to have a few extra tomatoes on hand, as the size and moisture content can vary. Adjust the number of tomatoes based on your specific recipe and personal taste preferences.