Peanut butter vs Whey protein (1 scoop): which protein is cheaper?

Budget says one, calories say the other

Peanut butter costs $0.022 per gram of protein against $0.031, so it saves $6.47 a week at a 100 g/day target. Whey protein (1 scoop) answers a different question: 20.0 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.

On a cut these are not comparable

Whey protein (1 scoop) carries 4.7x 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 150 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

• Peanut butter vs Oats (dry)Whey protein (1 scoop) vs Oats (dry)
• Peanut butter vs Lentils (cooked)Whey protein (1 scoop) vs Lentils (cooked)
• Peanut butter vs Tofu (firm)Whey protein (1 scoop) vs Tofu (firm)
• Peanut butter vs Black beans (cooked)Whey protein (1 scoop) vs Black beans (cooked)
• Peanut butter vs Greek yogurt (nonfat)Whey protein (1 scoop) vs Greek yogurt (nonfat)
• Peanut butter vs Eggs (~2 large)Whey protein (1 scoop) vs Eggs (~2 large)
• Peanut butter vs Chicken breast (raw)Whey protein (1 scoop) vs Chicken breast (raw)
• Peanut butter vs Canned tuna (in water)Whey protein (1 scoop) vs Canned tuna (in water)

Frequently asked

Which is cheaper for protein, peanut butter or whey protein (1 scoop)?

Peanut butter, at $0.022 per gram of protein against $0.031 for whey protein (1 scoop) (July 2026 US grocery prices). A 30 g protein serving costs $0.66 vs $0.94.

Which has more protein per calorie, peanut butter or whey protein (1 scoop)?

Whey protein (1 scoop), with 20.0 g protein per 100 kcal against 4.3 g for peanut butter, 4.7x leaner. That matters when you are cutting and calories are the binding constraint.

Which should I buy, peanut butter or whey protein (1 scoop)?

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, whey protein (1 scoop) gives you 4.7x more protein per calorie and is usually worth its $0.031/g price.