Score any protein, in seconds.
Powders, shakes, bars, or whole foods. Compare efficiency, purity, value, and bioavailability on a single 0 to 10 score.
What are you scoring?
Sets bioavailability. Whey isolate absorbs at 98 percent; plant proteins typically range 86 to 91 percent.
Nutrition facts per serving
Penalized at 1.2x as a filler.
Adds a small bonus, capped at 1.5 points.
Leave blank to auto-estimate from calories.
Counts toward carbs.
Cost per serving (optional)
Benchmark: 18 g protein per $1 = 10 / 10 value.
Enter at least protein and calories. Your score will appear here.
Recent calculations
Up to 8 items. Stored in this browser only.
Save your first calculation to see it here
Run a score above, then tap Save calculation.
Compare proteins
Compare up to 3 at once. Use Add to compare on the score card.
Three steps to a real score.
Lookup or type a label, pick the source type, and read the breakdown.
Load a product
Search the USDA database in Lookup mode, or type values from any nutrition label in Manual entry.
Pick the source
Set the main protein source. This drives bioavailability, the 20 percent component that reflects digestion and amino acid quality.
Read the score
A 0 to 10 score breaks down across Efficiency 35%, Purity 25%, Value 20%, and Bioavailability 20%, with a small fiber bonus.
What each component means.
Four numbers, weighted, combine into a single 0 to 10 protein quality score.
Efficiency
How many calories come from protein. Leaner products carry less filler weight per gram of protein delivered.
Purity
Protein as a share of total macros. Sugar gets a 1.2x penalty as a filler; fiber adds a small bonus capped at 1.5 points.
Value
Grams of protein per dollar. Optional. Leave price blank and the three other components are re-weighted automatically.
Bioavailability
How efficiently the protein source is digested and used. Drawn from PDCAAS / DIAAS reference ranges by source type.
Bioavailability by source
| Protein type | Relative score |
|---|---|
| Whey Isolate | 98% |
| Whey Concentrate | 94% |
| Casein | 90% |
| Egg White | 95% |
| Animal Meat | 95% |
| Soy | 91% |
| Pea | 89% |
| Rice | 87% |
| Hemp | 86% |
| Collagen | 80% |
| Mixed Plant Blend | 88% |
What a good score looks like
- 9.0 – 10.0OutstandingTop tier: excellent efficiency, purity, and absorption.
- 8.0 – 8.9ExcellentHigh-quality protein with great value and nutrition.
- 7.0 – 7.9Very GoodSolid choice. Strong balance of quality and value.
- 6.0 – 6.9GoodDecent overall. Room to improve purity or efficiency.
- 5.0 – 5.9FairAverage. Consider alternatives for better value.
- Below 5.0Needs ImprovementLow efficiency or high fillers. Look for better options.
Frequently asked questions.
Quick answers about scoring, sources, and how to compare products.
Where the numbers come from.
Data sources
Scores are informed by PDCAAS (FAO/WHO, 1991) and DIAAS (FAO, 2013) frameworks, with bioavailability ranges drawn from peer-reviewed absorption research. Nutrition lookups query USDA FoodData Central. The 18 g protein per dollar value benchmark reflects 2025 U.S. supplement market averages.
- 01FAO/WHO PDCAAS Report (1991)
Original Protein Digestibility Corrected Amino Acid Score methodology
- 02FAO DIAAS Report (2013)
Updated Digestible Indispensable Amino Acid Score methodology
- 03NIH ODS: Protein Fact Sheet
U.S. government reference for protein quality and intake
- 04USDA FoodData Central
Source database for nutrition lookups and amino acid composition
Related guides
Long-form articles that go deeper on protein science, the math behind the score, and the products that score well.
Step-by-step Guide
Step 1: Enter Basic Nutrition Facts
Start with the essential information from your product label or nutrition database. Enter the product name (optional, helpful for tracking), protein in grams (the main protein content per serving such as 25g for a typical protein powder scoop), calories per serving (total calories in one serving), and fat in grams (optional, leave blank to auto-estimate from the other macros). Works for powders, shakes, bars, whole foods, and any protein source.
Step 2: Add Carbohydrate Details
Enter total carbohydrates, sugar (penalized at 1.2x because it acts as a filler), fiber (adds a small bonus up to 1.5 points), and optional sugar alcohols. Sugar is penalized more than regular carbs because it is treated as a filler. Fiber adds a small bonus because it is beneficial.
Step 3: Select Protein Source Type
Choose the main protein type. Animal sources (Whey Isolate at 98 percent, Whey Concentrate, Casein, Egg White, Animal Meat at 95 percent) typically absorb best. Plant sources (Soy, Pea, Rice, Hemp) typically range from 86 to 91 percent. Collagen and Mixed Plant Blend fall in between.
Step 4: Add Price (Optional)
Enter price per serving to include Value for Money in the score. The benchmark is 18 grams of protein per dollar for a top score (10 of 10). Skip this and the calculator re-weights the other components automatically.
Step 5: View Your Results
The calculator updates instantly. Read the overall score (0 to 10), quality rating (Outstanding, Excellent, Very Good, Good, Fair, or Needs Improvement), and breakdown across efficiency, purity, value, and bioavailability.
Score Tiers
9.0 to 10.0: Outstanding. Top-tier protein with excellent efficiency, purity, and absorption.
8.0 to 8.9: Excellent. High-quality protein that delivers great value and nutrition.
7.0 to 7.9: Very Good. Solid choice with a good balance of quality and value.
6.0 to 6.9: Good. Decent, with room for improvement in purity or efficiency.
5.0 to 5.9: Fair. Average quality. Consider alternatives for better value.
Below 5.0: Needs Improvement. Low efficiency or high fillers. Look for better options.
Data Sources
Protein quality scores are informed by PDCAAS (FAO/WHO, 1991) and DIAAS (FAO, 2013) frameworks, with bioavailability ranges drawn from peer-reviewed absorption research. Results are educational estimates, not medical advice.
- FAO/WHO PDCAAS Report (1991) — Original Protein Digestibility Corrected Amino Acid Score methodology
- FAO DIAAS Report (2013) — Updated Digestible Indispensable Amino Acid Score methodology
- NIH Office of Dietary Supplements: Protein — U.S. government reference for protein quality and intake
- USDA FoodData Central — Amino acid composition data for protein sources
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