Our methodology
A food rating is only as trustworthy as the method behind it — so here is exactly how the WoofScore is calculated.
The A–F scale
Every food is scored 0–100 and mapped to a letter grade: A (90+) excellent, B (68–89) good, C (52–67) average, D (44–51) poor, F (below 44) avoid. The grade is an ingredient-quality signal, not a complete nutritional analysis.
What raises the score
- Named animal proteins as the first ingredient (chicken, beef, salmon, named meat meals) — the strongest positive signal.
- Whole foods: vegetables, fruit, whole grains and named healthy fats and oils.
- Beneficial supplements: omega-3s, glucosamine/chondroitin, probiotics, taurine, chelated minerals.
What lowers the score
- Vague, unnamed proteins: "meat meal", "animal by-product meal", "animal digest".
- Cheap fillers: corn gluten meal, wheat middlings, brewers rice, powdered cellulose.
- Artificial colours & dyes (Red 40, Yellow 5/6, Blue 2, caramel colour).
- Added sugar & sweeteners, and controversial preservatives (BHA, BHT, ethoxyquin, propyl gallate).
How ingredient order is weighted
Ingredients are listed by weight, so an item near the top counts far more than one near the end. Positive ingredients are weighted by position; additives, colours and preservatives are penalised at full weight wherever they appear, because they matter regardless of quantity.
Grade caps
Any "avoid"-tier ingredient (e.g. an artificial colour or BHA) caps the maximum grade — a food with a banned-in-some-countries preservative cannot score an A no matter how good the rest of the recipe is.
Sources
Our criteria draw on AAFCO ingredient definitions, FDA pet-food guidance, and established veterinary-nutrition references. We lean cautious: where evidence is mixed, we flag an ingredient as "watch" rather than "safe".
Limitations
A WoofScore reflects the ingredient list, not lab testing of the finished food, sourcing quality, or your individual dog's needs. It is informational, not veterinary advice. For diet decisions — especially for puppies, seniors, or dogs with health conditions — talk to your vet.
Corrections
We update criteria and ratings when new evidence or a credible correction is raised. Email hello@woofscore.com.