Which is cheaper for protein, egg whites (liquid) or peanut butter?

Peanut butter, at $0.022 per gram of protein against $0.046 for egg whites (liquid) (July 2026 US grocery prices). A 30 g protein serving costs $0.66 vs $1.38.

Which has more protein per calorie, egg whites (liquid) or peanut butter?

Egg whites (liquid), with 21.0 g protein per 100 kcal against 4.3 g for peanut butter, 4.9x leaner. That matters when you are cutting and calories are the binding constraint.

Which should I buy, egg whites (liquid) or peanut butter?

Depends on your constraint. On a tight budget with room in your calories, peanut butter is cheaper per gram of protein. On a calorie-capped cut, egg whites (liquid) gives you 4.9x more protein per calorie and is usually worth its $0.046/g price.

Protein head-to-heads · July 2026

Egg whites (liquid) 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.

Peanut butter is 2.1x cheaper per gram of protein ($0.022/g vs $0.046/g), while Egg whites (liquid) is the leaner choice at 21.0 g protein per 100 kcal against 4.3 g. Budget favours one, a calorie cap favours the other.

Food	$/g protein	30 g protein costs	You need	kcal that come with it	Protein/100 kcal
Egg whites (liquid)	$0.046	$1.38	275 g	143 kcal	21.0 g
Peanut butter	$0.022	$0.66	120 g	706 kcal	4.3 g

Full macros, per serving

Food (per serving)	Price	kcal	Protein	Carbs	Fat
Egg whites (liquid) (100 g)	$0.50	52	10.9 g	0.7 g	0.2 g
Peanut butter (100 g)	$0.55	588	25 g	20 g	50 g

A week of protein from each

Hitting a common 100 g/day protein target from peanut butter alone costs $15.40 a week; from egg whites (liquid) alone, $32.11. That is a gap of $16.71 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

Peanut butter costs $0.022 per gram of protein against $0.046, so it saves $16.71 a week at a 100 g/day target. Egg whites (liquid) answers a different question: 21.0 g of protein per 100 kcal against 4.3 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 peanut butter brings 706 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.

One of these is a convenience purchase

Egg whites (liquid) ranks #20 of 25 on cost per gram of protein, near the bottom. It is not a bad food, it is an expensive way to buy protein: $1.38 per 30 g against $0.66 for peanut butter. If it is in your basket for the protein, swap it. If it is there because it travels well or you enjoy it, that is a different and perfectly good reason.

On a cut these are not comparable

Egg whites (liquid) carries 4.9x the protein per calorie that peanut butter does. When you are eating at a deficit, that ratio is the whole game: the same 30 g of protein arrives with 143 kcal from one and 706 kcal from the other. The cheaper option stops being cheaper once you count what you had to give up elsewhere to fit it in.

Compare against other foods

Frequently asked

Which is cheaper for protein, egg whites (liquid) or peanut butter?: Peanut butter, at $0.022 per gram of protein against $0.046 for egg whites (liquid) (July 2026 US grocery prices). A 30 g protein serving costs $0.66 vs $1.38.
Which has more protein per calorie, egg whites (liquid) or peanut butter?: Egg whites (liquid), with 21.0 g protein per 100 kcal against 4.3 g for peanut butter, 4.9x leaner. That matters when you are cutting and calories are the binding constraint.
Which should I buy, egg whites (liquid) or peanut butter?: Depends on your constraint. On a tight budget with room in your calories, peanut butter is cheaper per gram of protein. On a calorie-capped cut, egg whites (liquid) gives you 4.9x more protein per calorie and is usually worth its $0.046/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.