Protein Quality Calculator
"High protein" on the front of a pack doesn't tell you much. Enter what's on the nutrition label and the main protein source, and see how much usable protein you actually get for the calories and the price.
Protein score
Based on the label values you entered.
What the score means
The score is usable protein per 100 calories. It combines two things labels don't show together: how much of the food's energy is protein, and how well your body can use that protein.
Why protein quality matters
Proteins differ in their essential amino acids and how well they're digested. Nutrition scientists capture this with scores like PDCAAS (protein digestibility-corrected amino acid score), which runs from 0 to 1. Whey, milk and egg proteins score 1. Collagen scores 0 because it lacks the essential amino acid tryptophan, so a collagen bar can say "18 g protein" while contributing very little complete protein.
We multiply the protein grams by the source's PDCAAS to estimate usable protein. Values are typical published figures; blends (for example pea plus rice) usually score higher than either alone, and processing changes them, so treat the result as a guide. If a product mixes sources, choose the first protein in its ingredient list.
Questions
Why PDCAAS and not DIAAS?
DIAAS is the newer, more precise method, but published DIAAS values exist for far fewer foods. PDCAAS gives a consistent comparison across everyday products. Both agree on the big picture: animal proteins and soy score high, collagen scores zero.
Is a "Low" food bad for me?
No. It just isn't an efficient protein source. Plenty of nutritious foods score low here because their calories come mainly from carbs or healthy fats.
Does it work for whole meals?
It's built for single products with one main protein. Meals mix several proteins that complement each other, which this simple score can't capture.