How Many Diced Tomatoes In a Can? | A Quick Conversion Guide

A standard 14.5-ounce can of diced tomatoes holds about 1.8 cups and is equivalent to roughly 5 to 6 small fresh tomatoes.

You open a recipe that calls for one can of diced tomatoes, but your kitchen has only fresh ones from the farmer’s market. Or you’re doubling a stew and need to know if two 14.5-ounce cans equal one 28-ounce can. The answer depends on how you measure — total volume, drained weight, or fresh equivalency.

A standard 14.5-ounce can of diced tomatoes holds roughly 1.8 cups of total content, while a 28-ounce can holds about 3.5 cups. In terms of fresh tomatoes, that translates to about 5 to 6 small tomatoes for the smaller can and 10 to 12 for the larger one. This guide walks you through the conversions so you can confidently swap between canned and fresh.

Standard Can Sizes and Their Tomato Counts

Most recipes refer to the two most common retail sizes: 14.5 ounces (411 grams) and 28 ounces (794 grams). A 14.5-ounce can contains about 5 to 6 small whole tomatoes that have been peeled, chopped, and packed in tomato juice. A 28-ounce can holds roughly 10 to 12 small tomatoes — about double the quantity.

Other can sizes exist, especially in commercial or international kitchens. A No. 2 can holds 18 to 20 ounces (about 2½ cups), and a No. 2½ can holds 27 to 29 ounces (about 3 cups). A 680-milliliter can, common outside the US, equals roughly 23 fluid ounces.

For most home cooks, sticking with the 14.5-ounce or 28-ounce can will cover nearly any recipe that calls for diced tomatoes. If you see a recipe calling for a “28-ounce can,” that typically means total weight including liquid.

Why the Can-Size Confusion Sticks

The confusion around canned tomato quantities comes from inconsistent labeling. Some labels list total weight, others list drained weight, and recipes rarely specify which you should measure. To make matters more confusing, different brands pack their cans with slightly different amounts of liquid.

Here are the cup equivalents for the most common can sizes, based on total contents (solids and liquid):

• 14.5-ounce can: Approximately 1.8 cups of total content.
• 28-ounce can: Approximately 3.5 cups of total content.
• No. 2 can (18–20 oz): About 2.5 cups total.
• No. 2½ can (27–29 oz): About 3 cups total.
• 680-ml can (international): About 2.8 cups total.

Knowing these cup measures helps you scale recipes accurately. If your recipe calls for “one 28-ounce can” and you only have 14.5-ounce cans, you’ll need two of them to reach a similar total volume.

From Canned to Fresh: Making the Switch

Swapping fresh tomatoes for canned is straightforward once you know the volume equivalence. One cup of canned diced tomatoes (drained) weighs roughly 7.5 ounces, according to the drained weight per cup guide on Thespicetrain. A cup of canned tomatoes including the liquid is closer to 1½ cups of cooked fresh tomatoes. To replace a 14.5-ounce can of diced tomatoes, use about 5 to 6 small fresh tomatoes or 1½ cups of chopped fresh tomatoes.

The following table summarizes the fresh-to-canned substitutions for the most common can sizes:

These numbers are approximations because tomato size and brand packing density vary. When substituting, start with the lower end of the range and adjust for your preferred texture and liquid content.

How to Handle Liquid and Texture

Canned diced tomatoes are packed in tomato juice or puree, and the liquid can make a big difference in your dish. Here’s how to choose whether to drain or keep the liquid:

1. Use undrained for sauces, soups, and stews — the extra liquid adds body and tomato flavor to the dish. You may need to simmer longer to thicken.
2. Drain for salsas, salads, or baked dishes where watery juice could dilute the final product. Brush off excess liquid with a fine-mesh strainer.
3. Reserve the drained juice — if you find the dish is too thick after draining, add a splash of the reserved juice to bring back moisture without adding extra volume.
4. Adjust cooking time when substituting fresh — fresh tomatoes release water as they cook, so you may need to simmer uncovered for a few extra minutes to achieve the same consistency.

If a recipe calls for diced tomatoes and you only have whole peeled tomatoes, crush or chop them before adding. Canned whole tomatoes lack the calcium chloride that helps diced pieces keep their shape, so they’ll break down more during cooking — a fine swap for sauces.

Brand Differences and What to Look For

Not all canned diced tomatoes are identical. Most brands pack their tomatoes in juice or puree, with calcium chloride added to help the pieces stay firm during cooking. Per the Del Monte diced tomatoes product page, their version is fat-free, preservative-free, and packed in tomato juice. Other major brands like Hunt’s use similar ingredients.

Store-brand cans often follow the same formula, but it’s worth checking the label for added sugar, salt, or citric acid. Some premium brands may use fire-roasted tomatoes or basil-lemon blends that change the flavor profile. For most recipes, the standard product works well.

Remember that 1 pound of fresh tomatoes equals about 3 medium tomatoes or 1½ cups of chopped tomatoes, a useful baseline if you’re working with a scale.

The Bottom Line

A 14.5-ounce can of diced tomatoes holds about 1.8 cups total and is equivalent to 1½ cups of chopped fresh tomatoes, while a 28-ounce can holds about 3.5 cups and equals 3 cups of fresh. Know the size you have, decide whether to drain, and you can substitute with confidence.

For the most accurate substitution, match the volume of the can’s total contents to the same amount of fresh chopped tomatoes using a liquid measuring cup — your recipe will turn out exactly as intended.