The protein in a full pack depends on its food weight and labeled protein basis. Counting printed servings alone is not enough when two products use different serving sizes. Keep package amount and the portion you intend to eat separate.
Compare two invented packs
Pack A weighs 400 g and lists 10 g protein per 100 g. Its calculated package total is 40 g. Pack B weighs 300 g and lists 8 g protein per 60 g serving. It contains five such servings, for 40 g protein in the pack. Different package sizes and serving figures can produce the same package protein total.
That does not make the foods identical
One 100 g portion of A supplies 10 g; the same 100 g weight of B supplies about 13.3 g under the uniform-product assumption. The package total answers how much protein is available across the whole pack, while equal-weight density answers another question.
Useful for a cost comparison
If you use the entire pack, price divided by package protein gives a cost per gram. If part is discarded or inedible, the usable total may differ. Do not include packaging mass or turn drained and undrained weights into interchangeable amounts.
FDA’s serving guidance supports scaling the recorded quantity. The example is invented, and the figures should not be attached to real products. Use the protein-cost tool only after entering matching edible weight and label basis. A pack with more total protein can still be a less practical purchase if the amount exceeds what you will use.
Sources and example boundaries
- FDA: serving information
Serving sizes and household/metric units on U.S. labels.
All food figures and prices in the worked example are invented to explain the method. They are not restaurant nutrition, tested recipes, shopping prices or personal dietary advice. Use the current label for the product you actually have.