Methodology

How PetFoodRate scores every product

Every product receives a single A to E grade composed from five sub-scores. No human judgment, no sponsor influence, no black-box AI. The algorithm is deterministic and reproducible.

The A to E grade at a glance

A

Excellent 85 to 100

B

Good 70 to 84

C

Average 55 to 69

D

Poor 40 to 54

E

Avoid 0 to 39

The five sub-scores

01

Proteins

We weigh each protein source by quality, traceability, and species fit. Named whole meats ('fresh chicken', 'salmon') score higher than generic 'meat meal' or 'animal by-products'. Position in the ingredient list also matters: the first three positions carry more weight than positions 10 and below.

02

Nutrition balance

Crude protein, fat, ash, fibre, and moisture levels are compared to species-specific needs. A 35 percent protein kibble is excellent for a ferret but excessive for a senior rabbit. We adjust the grade by species, not with a flat rule.

03

Undesirables

Artificial colours, BHA and BHT preservatives, ambiguous 'flavour enhancers', unnamed by-products, and excessive fillers pull the grade down. We list every flagged ingredient in the product page so you can verify.

04

Transparency

Does the label name specific ingredients ('chicken' vs 'poultry meal')? Does it declare precise percentages? Is the country of origin listed? Transparency rewards brands that let you verify what you're feeding.

05

Species adaptability

The same ingredient can be excellent for one species and harmful for another. Taurine is essential for cats but neutral for dogs. Alfalfa is great for rabbits but inappropriate for ferrets. Our database scores every ingredient per species and the final grade reflects this.

What we do NOT do

  • No payment to change a grade - Brands cannot buy their way up. Never.
  • No opaque scoring - Every ingredient, sub-score, and weight is visible on every product page.
  • No moral judgment - We do not rate the brand, packaging, or marketing. We rate the composition and its species fit.
  • No medical advice - Our grades are informational. For medical decisions about your pet's diet, consult a veterinarian.

Updates and revisions

Our ingredient database is reviewed at least twice a year. When a brand changes its formulation or a scientific study revises an ingredient, affected grades are recomputed automatically. Revision history is public.