Protein Density: Why Protein Per 100 Calories Matters
Protein density is grams of protein per 100 calories. Under 10 is weak, 10 is good, 15 is great and 20 or more is elite. StarKist tuna pouches hit 24.3.
Top picks
Densest whole food
StarKist Chunk Light Tuna in Water17 g protein · 70 cal · 24.3 g per 100 cal
Ingredients: tuna, water, broth, salt.
- Amazon
- Amazon
- Amazon
The 10 densest products that pass
- 30 g12025 g
- 40 g16025 g
- 25 g10025 g
- 25 g10025 g
- 20 g8025 g
- 15 g6025 g
- 15 g6025 g
- 10 g4025 g
- 42 g17024.7 g
- 17 g7024.3 g
How to calculate
Divide protein grams by calories, then multiply by 100. A 150-calorie snack with 30g of protein scores 20. One with 15g scores 10. Both pass the rule, but the first gives twice the protein for the same calories. The protein density calculator does the math for any label.
Grade bands
- 20 or more: elite. Tuna, broth, whey isolate, 30g+ shakes.
- 15 to 20: great. Most 30g shakes, Greek yogurt, the better jerky.
- 10 to 15: good. Most jerky, roasted edamame, the better bars.
- Under 10: weak. Cookies, snack mix, most vegan bars.
The ceiling
Protein carries 4 calories per gram, so 25g per 100 calories is the hard maximum: a food made of nothing but protein. A product that lists more than that has protein and calorie numbers that cannot both be true. 180cal holds those back until the label is checked.
Where it misleads
- Small servings: broth scores high on just 10g.
- Powders: the label is one scoop with water. Mix-ins count on top.
- Multi-serving bags: the numbers cover one serving, not the bag.
- Everything else: density ignores taste, ingredients and price.
How we rank
Every product here lists more than 8g protein, 180 calories or fewer per serving. Anything that misses either line is out, with no exceptions.
We rank by protein per 100 calories, using the protein, calories and price on the Amazon listing as last checked on Nov 4, 2026. Listings whose numbers can't all be true are held back until we check the label. Confirm the live listing and the package before you buy.
180cal earns a commission on Amazon purchases. It never changes which products pass or how they rank.
Questions about protein per 100 calories
What is protein density?
Protein density is how much protein a product gives for its calories, shown here as grams of protein per 100 calories. Divide protein by calories and multiply by 100.
Is 10g of protein per 100 calories good?
Yes, 10 is good. At 10, 40% of the calories come from protein. 15 is great and 20 or more is elite. Most protein bars sit near 10, while plain tuna and the best shakes score above 20.
What has the highest protein density?
Foods that are close to pure protein. Whey powders, bone broth powder, plain tuna and chicken, and the leanest 30g and 40g shakes all list about 24 to 25g per 100 calories. Protein carries 4 calories per gram, so 25 is the hard maximum.
Why does 180cal show protein per 100 calories?
It lets you compare products with different serving sizes and calorie counts on one number, instead of trusting protein grams alone.
Does high protein density mean a product is healthy?
No. 180cal uses protein density for snack comparison, not medical or dietetic advice. Still check ingredients, allergens and the label.