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Protein head-to-heads · July 2026

Wheat flour (all-purpose) vs Peanut butter: 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.

Wheat flour (all-purpose) is 1.9x cheaper per gram of protein ($0.012/g vs $0.022/g), while Peanut butter is the leaner choice at 4.3 g protein per 100 kcal against 2.8 g. Budget favours one, a calorie cap favours the other.

Food$/g protein30 g protein costsYou needkcal that come with itProtein/100 kcal
Wheat flour (all-purpose)$0.012$0.35291 g1060 kcal2.8 g
Peanut butter$0.022$0.66120 g706 kcal4.3 g

Full macros, per serving

Food (per serving)PricekcalProteinCarbsFat
Wheat flour (all-purpose) (100 g)$0.1236410.3 g76.3 g1 g
Peanut butter (100 g)$0.5558825 g20 g50 g

A week of protein from each

Hitting a common 100 g/day protein target from wheat flour (all-purpose) alone costs $8.16 a week; from peanut butter alone, $15.40. That is a gap of $7.24 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

Wheat flour (all-purpose) costs $0.012 per gram of protein against $0.022, so it saves $7.24 a week at a 100 g/day target. Peanut butter answers a different question: 4.3 g of protein per 100 kcal against 2.8 g, which is what matters once calories, not dollars, are the thing you run out of first.

What the calories cost you

Getting 30 g of protein from wheat flour (all-purpose) brings 1060 kcal with it. On a 2,000 kcal day, three servings would be most of your budget before anything else goes on the plate. That is fine when you are eating at maintenance or building, and it is the reason this food falls apart on a cut no matter how good the price per gram looks.

Two budget staples, so the tiebreak is elsewhere

Both of these sit in the cheapest third of everything we track (#3 and #7 of 25), and the difference between them is $0.31 per 30 g of protein. That is small enough that shelf life, prep time and whether you will actually eat it should decide this, not the price column.

Compare against other foods

Frequently asked

Which is cheaper for protein, wheat flour (all-purpose) or peanut butter?
Wheat flour (all-purpose), at $0.012 per gram of protein against $0.022 for peanut butter (July 2026 US grocery prices). A 30 g protein serving costs $0.35 vs $0.66.
Which has more protein per calorie, wheat flour (all-purpose) or peanut butter?
Peanut butter, with 4.3 g protein per 100 kcal against 2.8 g for wheat flour (all-purpose), 1.5x leaner. That matters when you are cutting and calories are the binding constraint.
Which should I buy, wheat flour (all-purpose) or peanut butter?
Depends on your constraint. On a tight budget with room in your calories, wheat flour (all-purpose) is cheaper per gram of protein. On a calorie-capped cut, peanut butter gives you 1.5x more protein per calorie and is usually worth its $0.022/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.