How the Nutri-Score Algorithm Really Works
In short
The Nutri-Score adds up negative points (energy, sugars, saturated fat, salt, sweeteners) and positive points (fibre, protein, fruit and vegetables), using one of 3 separate scoring grids (solid foods, fats, beverages). The algorithm was revised in 2022-2023 and applied in France since 16 March 2025.
The Nutri-Score looks simple from the outside: a letter, a colour. Behind it, it's a multi-step calculation, with different point grids depending on the food type, and a scientific revision that changed the thresholds in 2023. That level of detail isn't necessary for everyday use of the logo — but it helps explain why two seemingly similar products sometimes land on different letters, and why the logo has limits, documented by its own scientific committee.
The general principle: a points balance, per 100g
The calculation is always done per 100g or 100ml of product, never on the portion actually eaten. A total of negative points is calculated first, then a total of positive points, and the difference between the two gives a numeric score, then converted into a letter from A to E using thresholds specific to each scoring grid. It's a system developed under the scientific responsibility of the European Nutri-Score scientific committee, run in France by the national public health agency.
Negative points: what penalises the score
Four elements are counted as negative points, each on a scale generally running from 0 to 10 (up to 15 for energy and sugars since the 2023 revision):
- Energy (in kJ per 100g)
- Sugars (in g per 100g)
- Saturated fat (in g per 100g)
- Salt (sodium × 2.5, in g per 100g)
Since the revision, a fifth element has been added: non-nutritive sweeteners (aspartame, stevia and other sugar substitutes) now carry their own negative points, a nuance that didn't exist in the original algorithm.
Positive points: what improves the score
Four elements are counted as positive points:
- Fibre
- Protein
- Fruit, vegetables, legumes and nuts (as a percentage of the product)
- Rapeseed, walnut and olive oils, specifically credited within the fats category
One important rule: if the total negative points exceed 11 (outside beverages), "protein" points are only counted if the "fruit and vegetables" score clears a certain threshold — a clause added to stop a very calorie-dense, salty product from being "saved" purely by its protein content.
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The calculation doesn't use the same points-to-letter conversion grid for every product. There are 3 official scoring grids: one for solid foods, one for added fats (oils, butters, margarines), and one for beverages. This split exists because an oil, being by nature almost entirely fat, can't be judged on the same grid as a ready meal: without a dedicated grid, every oil would end up at the bottom of the scale, including olive oil, whose unsaturated fat content is nonetheless recommended in reasonable amounts. For beverages, the grid is different again: water stays the reference at the top of the scale, and the sugar threshold is markedly stricter than for a solid food, since a sugary drink is consumed faster and without a comparable satiety effect.
The 2022-2023 revision: what actually changed
The European scientific committee (Belgium, France, Germany, Luxembourg, the Netherlands, Spain, Switzerland) approved a revision of the algorithm to better reflect dietary recommendations and the changing food supply. The new calculation took effect in Germany, Belgium, Switzerland and the Netherlands on 1 January 2024, in Luxembourg on 5 March 2024, and in France on 16 March 2025 (decree of 14 March 2025), with a two-year transition period to sell through existing packaging. The main documented effects: stricter thresholds on salt and sugar, better differentiation between wholegrain and refined cereals, and stronger penalties for red and processed meat.
The limits documented by the scientific committee itself
The Nutri-Score isn't presented by its designers as an absolute measure of "good" or "bad" food. Officially acknowledged limits include:
- It doesn't account for the degree of processing or additives — that's the role of other tools such as the NOVA classification, not its own.
- It compares poorly across different categories: the grid is designed to rank similar products against each other, not to compare an oil against a drink.
- Some energy-dense but nutritionally valuable foods (nuts, olive oil) can be penalised on the "energy" line, which is exactly why separate grids exist — to limit that bias.
- It rates a product, not an overall diet — frequency and quantities consumed are never accounted for by design.
These limits are documented in the scientific and technical publications of the Nutri-Score's own governing committee, which sets it apart from a marketing tool: its own designers publish its blind spots.
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Is the calculation done on the portion eaten or on 100g?
Always on 100g or 100ml of product, never on the portion actually eaten. That's exactly why you also need to check the serving size alongside the logo.
Why do oils have a separate scoring grid?
Because an oil is by nature almost entirely made of fat. Without a dedicated grid, every oil would score poorly, including olive oil, whose moderate consumption is recommended.
When did the new algorithm take effect in France?
On 16 March 2025, under the decree of 14 March 2025, with a two-year transition period to sell through existing packaging.
Knowing the algorithm's detail doesn't change how you use the logo in practice: compare like with like, check the actual serving size. Mostly, it helps show that the Nutri-Score isn't a black box, and that its own designers document its blind spots rather than presenting it as flawless. In Radish, every food shows its Nutri-Score computed with the official revised algorithm — try the app, free, your diary stays on your phone — never sent to our servers (except AI or barcode scanning, if you use them).
General information, not medical advice.
🔎 Methodology & sources. Every nutrition figure in this article is cross-checked against official sources (ANSES, EFSA, WHO, CIQUAL/USDA, French Public Health agency), and health topics are reviewed before publication against our internal reference framework. See our full methodology →
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