Methodology
Every Labelgrade is a transparent 0–100 score plus a letter grade, derived from a fixed formula applied to public USDA nutrition data. This page documents the formula, the data sources, our editorial process, and the limitations we know about.
What we score
The Labelgrade for a product is a weighted blend of measurable, publicly verifiable dimensions. Each dimension has its own 0–100 sub-score and letter grade displayed on every product page.
1. Protein density
Grams of protein per 100g of food. This is the most fundamental "how much protein is actually in this thing" metric — and it doesn't depend on arbitrary serving sizes that vary between brands and packages.
The score is computed as:
protein_density_score = min(100, 50 + (grams_protein_per_100g × 1.5))So an "empty" food (0 g protein per 100 g) floors at 50, the average packaged-food protein source (around 15 g/100 g) lands near 73, plain cooked chicken breast at 31 g/100 g reaches ~96, and an isolated whey concentrate (~80 g/100 g) maxes out at 100.
2. Ingredient quality
Starting from a base of 75, ingredient quality is adjusted up or down by the presence of specific markers:
| Marker | Adjustment |
|---|---|
| Soy protein concentrate / isolate (as chicken extender) | −5 |
| Phosphate additives (tricalcium, monocalcium, sodium) | −3 |
| Maltodextrin, dextrose, corn syrup | −2 |
| Artificial colors (Red 40, Yellow 5, etc.) | −5 |
| Artificial sweeteners (sucralose, aspartame, etc.) | −3 |
| Sugar alcohols (erythritol, xylitol, etc.) | −2 |
| Sodium > 600 mg per 100 g | −3 |
| Sodium < 200 mg per 100 g | +3 |
| Expeller-pressed or cold-pressed oils | +5 |
| Organic certification | +3 |
| First ingredient is "cultured", "pasteurized", or "Grade A" | +5 |
| Total ingredient list ≤ 5 items | +5 |
| Total ingredient list > 15 items | −3 |
The result is clamped to [0, 100]. The rule set is open and will evolve — see the public source code in our scoring repository (link will be enabled when we open-source the scoring module).
3. Protein per dollar (coming soon)
Verified retail pricing from major US retailers, normalized to grams of protein per US dollar. This dimension is not yet in the formula because we don't yet have a reliable pricing pipeline. When it lands, the weighting becomes density 40% + ingredient quality 30% + per-dollar 30%.
How letter grades map to scores
| Letter | Score range |
|---|---|
| A+ | 95 – 100 |
| A | 90 – 94 |
| A− | 85 – 89 |
| B+ | 80 – 84 |
| B | 75 – 79 |
| B− | 70 – 74 |
| C+ | 65 – 69 |
| C | 60 – 64 |
| C− | 55 – 59 |
| D | 40 – 54 |
| F | 0 – 39 |
Data sources
- USDA FoodData Central (primary). The federal government's open nutrition database. We pull from the Branded Foods set, accessed via api.data.gov. Every product page cites the USDA FDC ID and a direct link back to the source entry.
- Open Food Facts (secondary). Used where USDA doesn't have coverage, especially for international or niche brands. Always flagged on the page when used.
- Manufacturer label images (verification). For the top 10% of pages by traffic, we manually cross-check USDA numbers against the current retail label image, photographed in store or sourced from the retailer's product detail page.
Editorial process
- Ingestion. A product is pulled from USDA, normalized, and stored locally as JSON.
- Brief. A scoring brief is generated automatically from the JSON + sibling-category context.
- Writing. Each post is written by Labelgrade's editorial team using the brief as the input. Every numeric claim must match the brief or be flagged.
- Verification. Before publishing, a verification step checks every number against the source data; mismatches block publish.
- Publish. The post goes live with the source citations and a "Last verified" timestamp.
- Refresh. Top-traffic pages are re-verified monthly; all pages quarterly. Refreshes update the "Last verified" date even when no values change.
Corrections
If you spot an inaccuracy on any page, please contact us. Confirmed corrections are logged on our corrections page and the affected page is updated within 24 hours. We do not silently edit numeric claims — corrections are dated and described.
Conflicts of interest
Labelgrade participates in retailer and brand affiliate programs (Amazon Associates and others — see /affiliate-disclosure). A click-through that results in a purchase may earn Labelgrade a commission at no extra cost to the buyer.
Affiliate relationships do not affect the Labelgrade score for any product. The score is computed by the formula above applied to public data, before any affiliate consideration. We do not accept sponsored placements, paid reviews, or compensation in exchange for higher grades or favorable coverage. If we ever do, this page will be updated to disclose it.
What this scoring does not capture
- Total nutrition. Labelgrade is a protein-and-quality score. It is not a verdict on whether a food is "healthy" for any particular person or diet.
- Allergies and intolerances. We list ingredients but don't compute allergen warnings. Always read the actual product label.
- Taste, texture, or culinary fit. We're scoring the nutrition label, not the eating experience.
- Environmental, ethical, or sourcing claims. A higher Labelgrade does not mean a product is better for the planet, more humanely produced, or sourced from any particular region.
- Cost (yet). Until protein-per-dollar lands in the formula, we only consider the nutrition label.
Frequently Asked Questions
What is a Labelgrade?
A Labelgrade is a transparent 0–100 score plus a letter grade (A+ through F) that summarizes how well a specific branded food delivers protein, given its ingredient quality and (eventually) cost. We compute it from publicly verifiable nutrition data — primarily USDA FoodData Central — using a fixed formula published on this page.
How is the score calculated?
The current overall score is a weighted blend: protein density (60%) + ingredient quality (40%). Protein per dollar is being added as a third dimension once we have verified retail pricing for each product; the formula will then become density (40%) + ingredient quality (30%) + per-dollar (30%).
What sources do you use?
Primary source: USDA FoodData Central Branded Foods database, accessed via the api.data.gov API. Secondary: Open Food Facts for products USDA does not cover. Tertiary: manufacturer label images for spot-verification when high-traffic pages are refreshed. Every published grade cites the source IDs and access dates.
How often is each product re-verified?
Every published product page is re-verified at least once per quarter. Pages in the top 10% of monthly traffic are re-verified monthly. When USDA data changes or a manufacturer reformulates, the page is updated and the "Last verified" date is bumped.
Do you accept money to change grades?
No. Grades are determined by the formula on this page applied to public data. We participate in affiliate programs (see /affiliate-disclosure) so a click-through to buy a product may earn Labelgrade a commission, but the Labelgrade score itself is not for sale and is not affected by affiliate relationships.
Are you medical professionals?
No. Labelgrade is an editorial site, not a medical resource. We publish nutrition facts and our editorial assessment. Always consult a registered dietitian, doctor, or other qualified professional for medical or dietary advice — especially if you have allergies, kidney disease, diabetes, or other conditions where nutrition specifics matter.
What are the limitations?
USDA Branded Foods data is updated monthly but new product submissions stopped flowing from Label Insight in November 2023, so some recently reformulated products may have outdated values. Where we detect a discrepancy with the current retail label, we verify against the actual package and update. Our scoring formula is also intentionally narrow — it grades for protein delivery and ingredient simplicity, not overall nutrition or fitness for any particular diet.