A 15 oz can of tomato sauce holds about 1 3/4 cups. Tomato sauce is a smooth, pourable liquid, so it measures cleanly in a jug — pour the can in and it settles at just under the 2-cup mark. The figure is approximate because a can is sold by weight, and 15 oz of sauce is about 425 g, which at 245 g per cup (the USDA figure for tomato sauce) works out to about 1 3/4 cups. The small gap between the weight and the volume is the sauce clinging to the inside of the can, which is why you should always rinse the can with a splash of water and add that to the pan — it gets the last of the sauce out and the water is part of the recipe anyway.
Tomato sauce is the workhorse of weeknight cooking: pizza sauce, pasta sauce, enchilada sauce, shakshuka, and the base of countless soups and stews all start with a can of it. Recipes almost always measure it in cups, while shops sell it in cans, and the 1 3/4 cup figure is the bridge between the two. A recipe calling for 3 1/2 cups needs two cans; a recipe calling for 1 cup needs a little more than half a can. Knowing this stops the mid-recipe discovery that you are short, which is the moment when dinner gets delayed by twenty minutes.
Can of tomato sauce conversion table
The table below breaks a 15 oz can into fractions, with tablespoons and fluid ounces alongside. Tomato sauce is a liquid, so the volume fractions are reliable — unlike chunky canned tomatoes, there are no air gaps to worry about.
| Amount | Cups (approx.) | Tablespoons | Fluid ounces |
|---|---|---|---|
| 1/4 can | 0.44 cups (about 1/2 cup) | 7.0 tbsp | 3.5 fl oz |
| 1/2 can | 0.88 cups (about 7/8 cup) | 14.0 tbsp | 7.0 fl oz |
| 3/4 can | 1.31 cups (about 1 1/4 cups) | 21.0 tbsp | 10.5 fl oz |
| Full can | 1.75 cups (about 1 3/4 cups) | 28.0 tbsp | 14.0 fl oz |
| 2 cans | 3.50 cups (about 3 1/2 cups) | 56.0 tbsp | 28.0 fl oz |
By weight, a 15 oz can is about 425 g. At the USDA figure of 245 g per cup, 1 3/4 cups weighs about 429 g — the two ways of measuring agree within a spoonful, which is why either figure works in practice.
Worked examples
Pizza sauce for four pizzas
A pizza night for four people needs about 1 cup of tomato sauce spread thinly across four bases — roughly 1/4 cup per pizza. One 15 oz can gives you 1 3/4 cups, so you have enough for the pizzas plus 3/4 cup left over for dipping or for a second batch. Season the sauce simply: a pinch of salt, a crushed garlic clove, a drizzle of olive oil and a few torn basil leaves, stirred in cold. Do not cook pizza sauce before it goes on the pizza — it cooks in the oven, and pre-cooking it makes it too thick to spread.
Enchilada sauce for a tray bake
An enchilada recipe for six calls for 3 cups of tomato sauce, simmered with chilli powder, cumin and garlic. Two cans give you 3 1/2 cups, so use both and keep the extra 1/2 cup aside — it is exactly the right amount to spoon over the top of the finished tray before it goes in the oven. Simmer the sauce for ten minutes before assembling so the spices bloom, and taste for salt at the end, because canned sauce varies in saltiness between brands and you may not need to add any.
A quick pasta sauce for two
A pasta sauce for two people needs 1 cup of tomato sauce, heated with garlic, chilli flakes and a knob of butter. That is a little more than half a can — measure 1 cup into the pan and save the remaining 3/4 cup in a small container in the fridge. It will keep for two to three days and is enough for a shakshuka for one, a pan of beans in tomato sauce, or another round of pasta. Add a splash of the pasta cooking water to the sauce to loosen it and help it cling to the pasta.
How the figure is worked out
The figure above is worked out by simple division, not by guessing. The package weight is a standard 15 oz can of tomato sauce. Divide that weight by the grams in one cup and you get the number of cups in the package. Because cup weights for dry ingredients depend on how the cup is filled, the result is approximate, and the honest way to use it is as a planning figure: it tells you how many batches a bag will cover, not the exact cup count to the last spoonful. The cup weight used here is 245 g per cup, spooned and levelled, sourced from USDA.
Practical guidance
Tomato sauce is not the same as tomato passata, tomato paste, or crushed tomatoes, and the swap matters. Tomato sauce is smooth and already seasoned lightly; passata is uncooked and unseasoned; tomato paste is concentrated and must be diluted; crushed tomatoes are chunky. If a recipe calls for tomato sauce and you only have crushed tomatoes, blitz them smooth and the volume will be about the same. If you only have tomato paste, do not use it cup for cup — it is far too concentrated. Always check the label for added salt and sugar: some brands add a surprising amount of sugar, which changes a savoury sauce, and the salt level varies enough that you should taste before adding more.
Store leftovers properly. An opened can of tomato sauce keeps two to three days in the fridge in a glass or plastic container — never in the can, because the acid reacts with the metal. For longer storage, freeze it flat in a bag in 1-cup portions, and thaw in the fridge overnight or straight into a hot pan. Frozen sauce keeps for three months and is the easiest way to avoid wasting the 3/4 cup that is always left after a recipe that needs 1 cup.
Frequently asked questions
How many grams are in a can of tomato sauce?
About 425 g — a 15 oz can multiplied by 28.35 g per ounce. Using the USDA density of 245 g per cup, 1 3/4 cups weighs about 429 g, so the weight and volume figures agree within a spoonful. Use 425 g when a recipe works in grams.
Is tomato sauce the same as passata?
No. Tomato sauce is cooked and lightly seasoned; passata is raw, sieved tomatoes with no seasoning. They measure the same by volume, so you can swap them cup for cup, but passata needs seasoning and a longer cook to taste like sauce. If you use passata in place of sauce, add salt and simmer it for at least fifteen minutes.
Can I use crushed tomatoes instead of tomato sauce?
Yes, if you blitz them smooth. A 14.5 oz can of crushed tomatoes is also about 1 3/4 cups, so the volume matches. Blend the crushed tomatoes for a few seconds until smooth, then use exactly as the recipe directs. The flavour will be slightly fresher and less cooked, which is fine in most sauces.
How long does an opened can of tomato sauce keep?
Two to three days in the fridge in a non-metal container, or up to three months in the freezer. Transfer leftovers out of the can immediately — tomato acid reacts with the exposed metal and gives the sauce a metallic taste. Freeze in 1-cup portions so you can defrost exactly what you need.
Why is there sauce left in the can after pouring?
Tomato sauce is thick and clings to the inside of the can, so a can that holds 1 3/4 cups may only pour out 1 2/3 cups. Rinse the can with two or three tablespoons of water and add that to the pan — it recovers the sauce and the water belongs in the recipe anyway. A silicone spatula does the same job without the water.