I looked up the amount of carbs in tomato sauce on the Atkins meal tracker page but there are so many different results. When I make tomato sauce, I only use a few ingredients: olive oil, garlic, onion, tomato puree, crushed tomatoes and dried herbs. How many carbs do you think would be in say, 1/2 a cup?

Probably ~5-7g carbs per half cup, 1.5-2g of which are fiber, it depends on how thick or thin it is. I make my own, but usually just use tomato paste, OO, herbs, garlic & onion to get more tomato taste with the fewest carbs and lowest cost, and only add as much water as needed for my recipe. I use carb counts from the tomato can and look up the rest in http://nutritiondata.self.com/

Welcome to the forum!

MyFitnessPal (and likely other apps) has a recipe function. Put in exact amounts of ingredients, exact amount of servings..there's the answer. Save all your recipes, and soon you will have your own database. Though if you use recipes from well-known sources, e.g. WHeat Belly Bread, it may already be in the member created database. Custom your goals to low carb first.