Protein head-to-heads · July 2026
Canned tuna (in water) vs Split peas (cooked): 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.
Split peas (cooked) is 2.0x cheaper per gram of protein ($0.022/g vs $0.042/g), while Canned tuna (in water) is the leaner choice at 22.4 g protein per 100 kcal against 7.2 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 |
|---|---|---|---|---|---|
| Canned tuna (in water) | $0.042 | $1.27 | 115 g | 134 kcal | 22.4 g |
| Split peas (cooked) | $0.022 | $0.65 | 361 g | 419 kcal | 7.2 g |
Full macros, per serving
| Food (per serving) | Price | kcal | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| Canned tuna (in water) (100 g) | $1.10 | 116 | 26 g | 0 g | 1 g |
| Split peas (cooked) (100 g) | $0.18 | 116 | 8.3 g | 20.5 g | 0.4 g |
A week of protein from each
Hitting a common 100 g/day protein target from split peas (cooked) alone costs $15.18 a week; from canned tuna (in water) alone, $29.62. That is a gap of $14.43 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
Split peas (cooked) costs $0.022 per gram of protein against $0.042, so it saves $14.43 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 7.2 g, which is what matters once calories, not dollars, are the thing you run out of first.
The amount you actually have to eat
Thirty grams of protein means 361 g of split peas (cooked), against 115 g for canned tuna (in water). That is a real constraint, not a footnote: a price per gram only counts if the serving is one a person will finish. Treat split peas (cooked) as the base of a meal that other protein is added to, not as the protein itself.
What the calories cost you
Getting 30 g of protein from split peas (cooked) brings 419 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
Canned tuna (in water) carries 3.1x the protein per calorie that split peas (cooked) does. When you are eating at a deficit, that ratio is the whole game: the same 30 g of protein arrives with 134 kcal from one and 419 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
- Canned tuna (in water) vs Oats (dry)Split peas (cooked) vs Oats (dry)
- Canned tuna (in water) vs Peanut butterSplit peas (cooked) vs Peanut butter
- Canned tuna (in water) vs Lentils (cooked)Split peas (cooked) vs Lentils (cooked)
- Canned tuna (in water) vs Tofu (firm)Split peas (cooked) vs Tofu (firm)
- Canned tuna (in water) vs Black beans (cooked)Split peas (cooked) vs Black beans (cooked)
- Canned tuna (in water) vs Whey protein (1 scoop)Split peas (cooked) vs Whey protein (1 scoop)
- Canned tuna (in water) vs Greek yogurt (nonfat)Split peas (cooked) vs Greek yogurt (nonfat)
- Canned tuna (in water) vs Eggs (~2 large)Split peas (cooked) vs Eggs (~2 large)
- Canned tuna (in water) vs Chicken breast (raw)Split peas (cooked) vs Chicken breast (raw)
Frequently asked
- Which is cheaper for protein, canned tuna (in water) or split peas (cooked)?
- Split peas (cooked), at $0.022 per gram of protein against $0.042 for canned tuna (in water) (July 2026 US grocery prices). A 30 g protein serving costs $0.65 vs $1.27.
- Which has more protein per calorie, canned tuna (in water) or split peas (cooked)?
- Canned tuna (in water), with 22.4 g protein per 100 kcal against 7.2 g for split peas (cooked), 3.1x leaner. That matters when you are cutting and calories are the binding constraint.
- Which should I buy, canned tuna (in water) or split peas (cooked)?
- Depends on your constraint. On a tight budget with room in your calories, split peas (cooked) is cheaper per gram of protein. On a calorie-capped cut, canned tuna (in water) gives you 3.1x 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.