Protein Powder: Working Out Cost Per Serving
Cost per serving is price divided by servings per container. Cost per gram of protein is that figure divided again by protein grams per serving. Because scoop sizes differ between brands, price per tub and price per pound both mislead — a five-pound tub is not automatically better value.
Protein powder is the category where headline prices mislead most reliably. Tubs are sold by pounds, by kilograms, by grams and by servings, and scoop sizes differ between brands — so price per tub tells you very little.
The three numbers you need
- Servings per container — on the panel, above the ingredient list.
- Protein grams per serving — on the panel.
- Price — on Amazon at the moment you look.
Two calculations
Cost per serving = price ÷ servings per container. This is the figure to compare between products, and it is often the opposite ranking to price per tub.
Cost per gram of protein = cost per serving ÷ protein grams per serving. This is the more honest comparison when scoop sizes differ, which they usually do.
Why scoop size breaks the shortcut
A five-pound tub is not automatically better value than a two-pound tub. If the larger tub uses a 45 g scoop and the smaller uses a 30 g scoop, the larger provides proportionally fewer servings than its weight suggests. Manufacturers are not obliged to use the same scoop.
Where the servings figure gets slippery
Some products state “about” a number of servings. Some state a serving as two scoops. A few state servings based on a scoop size that differs from the scoop actually in the tub. The panel is the authority; the front of the tub is marketing.
A worked example
Tub A: 2 lb, 27 servings, 24 g protein each. Tub B: 5 lb, 68 servings, 24 g protein each. If A costs $30 and B costs $70, A is $1.11 per serving and B is $1.03 — a real but modest difference, and much smaller than the price gap implies.
Then check what else is in it
Cost per gram of protein is the right comparison only once you are comparing similar products. A concentrate and an isolate at the same cost per gram are not the same purchase — see isolate vs concentrate.
Our whey protein comparison shows pack size and servings per container together so the arithmetic is quick.
References
- NIH Office of Dietary Supplements — Dietary Supplements for Exercise and Athletic Performance
- NSF Certified for Sport