How scoring works

Principles

• Explainable. A score is never shown on its own. Every result lists the factors that raised or lowered it.
• Consistent. The same product shows the same score everywhere — search results, Today’s picks, alternatives, history and the detail page.
• Honest about gaps. Where the underlying data is thin, the app says so rather than inventing precision.

What goes into a score

Nutrition

Energy, sugars, saturated fat, salt, fibre and protein per 100g or 100ml. High levels of added sugar, saturated fat and salt push a score down; fibre and protein pull it up.

Ingredients

The ingredient list is read for whole-food ingredients, refined ingredients, and the position of sugars and fats in the list. A short list of recognisable ingredients scores better than a long list of refined ones.

Additives

Additives are identified by their E numbers and grouped by the level of concern reported in public references. A product can lose points for additives even when its nutrition is otherwise unremarkable.

Processing

Products are placed on the NOVA scale from 1 (unprocessed) to 4 (ultra-processed). NOVA 4 classification is one of the strongest downward factors in the score.

Labels and certifications

Nutri-Score, Eco-Score and certification labels present on the packaging are shown alongside the PureCheck score as context.

Reading the bands

• 75–100 — Low concern. Nothing checked exceeded its guideline level.
• 40–74 — Worth a closer look. One or more factors are worth reading before you buy.
• 0–39 — High concern. Several significant factors, listed in order of impact.

Worked examples

Three real results from the app:

• Quinoa, Simply Nature — 100. Nothing we checked exceeded its guideline level. NOVA 1, Nutri-Score A.
• Whole Wheat Bread, Trader Joe’s — 56. Worth a closer look: NOVA group 4, salt, and two additives.
• Milk Chocolate Bar, Ms Molly’s — 12. High concern: saturated fat, sugars, and NOVA group 4.

Point values shown on the marketing site (for example “high added sugar −18”) are illustrative of how factors combine, not a published weighting table.

Water scores

Water scores use a different input entirely: EPA-derived records for the public water system serving a ZIP code, including reported violations and open issues. A ZIP code can be served by more than one utility, and the report describes the system, not your building.

What a score cannot tell you

• Whether a product is safe for your allergy — always read the physical label.
• Whether it fits your medical needs, medication, or clinical diet.
• Portion size in your actual meal; scores are per 100g or 100ml.
• Anything the public data does not record. Missing data lowers confidence, not the score.

PureCheck is informational and does not replace professional medical advice.