How we score food

01

One score, three parts

Every product with an ingredient list gets one score from 0 to 100. The same product always gets the same score, for everyone. Without an ingredient list we don’t score a product at all, because any score would be a guess.

The formula

Score = 35% additives & ingredients + 45% nutrition + 20% processing

Each part is scored from 0 to 100. If a part can’t be worked out, it’s left out and the others are re-weighted, then the strictest cap that applies sets the maximum.

02

Additives & ingredients · 35%

This part starts at 100. Every additive and flagged ingredient is checked against our knowledge base and removes points by its concern tier, down to a minimum of 0.

High concernA regulator or strong research has raised a concern, such as a hazard classification or a ban elsewhere.−40
Moderate concernThere is evidence worth knowing about, such as an intake limit some people exceed or studies that raise questions.−20
Low concernA small or uncertain concern, such as a marker of ultra-processing.−6
No known concernNo known concerns at the levels permitted in food.0

Concern tiers are built from decisions by bodies such as EFSA, the WHO, IARC, the UK Food Standards Agency and the FDA, and from peer-reviewed research. Each flagged additive lists its reasons and sources. Browse every additive.

03

Nutrition · 45%

Fat, saturates, sugars and salt are graded Low, Med or High using the UK’s front-of-pack traffic-light thresholds. This part starts at 100 and each Med or High light removes points. Sugars count most.

Food, per 100 g
Nutrient	Low up to	High above	Med removes	High removes
Fat	3 g	17.5 g	−5	−20
Saturates	1.5 g	5 g	−10	−30
Sugars	5 g	22.5 g	−15	−40
Salt	0.3 g	1.5 g	−10	−30

Drinks, per 100 ml
Nutrient	Low up to	High above	Med removes	High removes
Fat	1.5 g	8.75 g	−5	−20
Saturates	0.75 g	2.5 g	−10	−30
Sugars	2.5 g	8 g	−20	−60
Salt	0.3 g	0.75 g	−10	−30

For drinks, sugars are High above 8 g per 100 ml, the higher band of the UK soft drinks industry levy, rather than the general front-of-pack value.

Fibre of 6 g or more per 100 g adds 10 points, and protein of 10 g or more adds 5 (food only). This part is capped at 100. We need at least 3 of the four traffic-light values; otherwise nutrition is left out of the score and the other parts are re-weighted. Missing data is never a reason to score lower (see below).

04

Processing · 20%

We use the NOVA scale, from 1 (unprocessed) to 4 (ultra-processed), as recorded by Open Food Facts.

NOVA 1UnprocessedWhole or minimally processed food, as close to nature as it gets.100
NOVA 2Culinary ingredientA basic kitchen ingredient like oil, butter, sugar or salt.90
NOVA 3ProcessedMade from whole foods with added salt, sugar or oil, like cheese, bread or tinned veg.65
NOVA 4Ultra-processedMade mostly from industrial ingredients rather than foods.30

The UK’s Scientific Advisory Committee on Nutrition (SACN, 2025) found that links between ultra-processed food and poorer health are consistent but come mostly from observational studies, and that NOVA has limits. Processing counts for a fifth of the score, alongside what’s actually in the food.

05

Caps

A product can’t average its way out of a serious problem. If one of these applies, the score is capped at about the maximum shown. Only the lowest cap that applies counts, and the app tells you which one it was.

Score caps, strictest first
When	Max	What the app says
Contains an ingredient of high concern	30	Capped at 30: contains an ingredient of high concern
Three or more of moderate concern	40	Capped at 40: contains 3 or more ingredients of moderate concern
Ultra-processed and high in sugar, salt or saturates	45	Capped at 45: ultra-processed and high in sugar, salt or saturates
Two of moderate concern	50	Capped at 50: contains 2 ingredients of moderate concern
High in sugar, salt or saturates	60	Capped at 60: high in sugar, salt or saturates
Ultra-processed (NOVA 4)	60	Capped at 60: ultra-processed
One of moderate concern	65	Capped at 65: contains 1 ingredient of moderate concern

“High in” means a red traffic light for sugars, salt or saturates, which the app names (for example, “high in sugars”). High fat counts too, unless the product also has 10 g of protein or more per 100 g, as seed and nut products often do. Fat and saturates in unprocessed foods and basic kitchen ingredients (NOVA 1 and 2), such as nuts, plain yoghurt or butter, never trigger a cap.

An ingredient of high concern caps any product at 30, whatever else is in it. There are 7 caps in all. Missing nutrition figures are never one of them (see below).

06

Missing data

Open Food Facts is built by volunteers, so figures are sometimes missing or typed wrong. Missing data never lowers or caps a score: we score what’s on record and say what isn’t.

“Our data looks incomplete” means a figure is missing or can’t be right. “Something doesn’t look right” means the gap probably flatters the product: with the amount typical for its kind of food (the median of UK products on Open Food Facts), it would score lower. That score is shown as unconfirmed rather than Great, and incomplete products are never suggested as alternatives. A photo of the nutrition panel fills the gap straight away.

07

Soft caps

Caps are soft, so capped products keep their order: a better product under the same cap still scores higher. A capped product scores between 40% of the cap (if everything else scored 0) and the full cap (if everything else scored 100):

capped = cap × (0.4 + 0.6 × average ÷ 100)

The score is whichever is lower: the weighted average or the capped value.

Worked example

Fizzbrook Original Cola

A fictional cola, per 100 ml: 10.6 g sugars.

Additives & ingredientsThree of moderate concern: 100 − 3 × 20: 40
NutritionSugars High for a drink: 100 − 60: 40
ProcessingUltra-processed (NOVA 4): 30
Weighted average0.35 × 40 + 0.45 × 40 + 0.2 × 30: 38.0
Soft cap: three or more of moderate concern (max 40)40 × (0.4 + 0.6 × 38.0 ÷ 100): 25.1

Score 25, Poor: “Scores low”. Capped at 40: contains 3 ingredients of moderate concern.

08

Verdicts

Every score falls into one of four bands, each with a fixed headline. A verdict rates the product, not the person, and what you do with it is up to you.

Bad: 0–24; Scores very low
Poor: 25–49; Scores low
Okay: 50–74; A mixed picture
Great: 75–100; Scores highly

09

What never changes a score

Your allergens, diet and watch list add personal alerts to a result, but they never change the score. That way a score means the same thing to everyone, and you can compare notes with anyone.

PureScan has no advertising, and no brand can pay to change a score or a rating. Scores are our assessment using this published method, not a regulatory judgement, and they aren’t medical advice.

10

Sources

Where the data and thresholds come from. Each additive page lists its own sources too.