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Protein head-to-heads · July 2026

Canned tuna (in water) vs Whey protein (1 scoop): which protein is cheaper?

USDA macros joined to current US grocery prices, reduced to the two numbers that decide it: dollars per gram of protein, and protein per calorie.

Whey protein (1 scoop) is 1.4x cheaper per gram of protein ($0.031/g vs $0.042/g), while Canned tuna (in water) is the leaner choice at 22.4 g protein per 100 kcal against 20.0 g. Budget favours one, a calorie cap favours the other.

Food$/g protein30 g protein costsYou needkcal that come with itProtein/100 kcal
Canned tuna (in water)$0.042$1.27115 g134 kcal22.4 g
Whey protein (1 scoop)$0.031$0.9438 g150 kcal20.0 g

Full macros, per serving

Food (per serving)PricekcalProteinCarbsFat
Canned tuna (in water) (100 g)$1.1011626 g0 g1 g
Whey protein (1 scoop) (30 g)$0.7512024 g3 g1.5 g

A week of protein from each

Hitting a common 100 g/day protein target from whey protein (1 scoop) alone costs $21.88 a week; from canned tuna (in water) alone, $29.62. That is a gap of $7.74 every week for the same protein. In practice you mix sources: the planner computes the cheapest mix for your exact target and calorie cap, live from the same dataset.

Budget says one, calories say the other

Whey protein (1 scoop) costs $0.031 per gram of protein against $0.042, so it saves $7.74 a week at a 100 g/day target. Canned tuna (in water) answers a different question: 22.4 g of protein per 100 kcal against 20.0 g, which is what matters once calories, not dollars, are the thing you run out of first.

Compare against other foods

Frequently asked

Which is cheaper for protein, canned tuna (in water) or whey protein (1 scoop)?
Whey protein (1 scoop), at $0.031 per gram of protein against $0.042 for canned tuna (in water) (July 2026 US grocery prices). A 30 g protein serving costs $0.94 vs $1.27.
Which has more protein per calorie, canned tuna (in water) or whey protein (1 scoop)?
Canned tuna (in water), with 22.4 g protein per 100 kcal against 20.0 g for whey protein (1 scoop), 1.1x leaner. That matters when you are cutting and calories are the binding constraint.
Which should I buy, canned tuna (in water) or whey protein (1 scoop)?
Depends on your constraint. On a tight budget with room in your calories, whey protein (1 scoop) is cheaper per gram of protein. On a calorie-capped cut, canned tuna (in water) gives you 1.1x more protein per calorie and is usually worth its $0.042/g price.

Prices are representative US grocery prices as of July 2026; your store will differ. Educational content, not medical or dietary advice. Dataset: free download, CC-BY.