How does the Nutri-Score work? A comprehensive guide

January 7, 2026 •

4 min read

According to scientific studies, the Nutri-Score is one of the most effective front-of-pack food labeling systems for helping consumers understand nutritional information at a glance. This simple, color-coded label is based on a complex algorithm that balances beneficial and less beneficial nutrients to generate an overall score.

Quick Summary

The Nutri-Score system rates food's nutritional quality using a color-coded A-to-E scale, calculated per 100g or 100ml. The calculation weighs favorable nutrients like fiber and protein against less favorable ones such as sugar and saturated fats. It helps consumers quickly compare products within the same category to guide healthier purchasing decisions.

Key Points

Positive vs. Negative: The Nutri-Score is calculated by subtracting points for favorable nutrients (protein, fiber, fruits, vegetables, nuts) from points for unfavorable ones (calories, sugar, saturated fat, sodium).
5-Color Scale: The final numerical score is converted into a letter (A to E) and color (dark green to dark orange) rating, representing the product's overall nutritional quality.
Per 100g/100ml Basis: All calculations are based on the nutritional values per 100 grams or 100 milliliters, which allows for consistent comparison between products.
Voluntary Label: The Nutri-Score is a voluntary label that food manufacturers can choose to display on their packaging, though many countries have adopted it.
Category-Specific Comparisons: The label is most useful for comparing the nutritional quality of similar products within the same food category, not for comparing different food types.
Updated Algorithm: The calculation algorithm has been updated over time (e.g., the 2024 update) to reflect modern dietary guidelines and improve product classification.
Limitations: Critics note that the score can be an oversimplification, does not consider portion size, and may penalize some genuinely healthy foods.

Understanding the Nutri-Score System

The Nutri-Score is a voluntary front-of-pack food label that aims to simplify nutritional information for consumers. Using a clear five-color scale, it helps individuals quickly assess the nutritional quality of products and make more informed food choices. The colors range from dark green (A) for the highest nutritional quality to dark orange (E) for the lowest. This system is particularly useful for comparing processed products, where nutritional values can vary significantly between similar items.

The Science Behind the Score

The Nutri-Score algorithm was developed by independent scientists based on the UK Food Standards Agency's nutrient profiling system. It evaluates a product based on its content per 100 grams or 100 milliliters. It assigns points to both 'favorable' and 'unfavorable' nutritional components, then balances them to arrive at a final score.

The 'Negative' Components

These are the nutrients for which a product receives penalty points. The higher the content of these elements per 100g/100ml, the more points are added to the negative score.

Energy (kJ): Calories from the product.
Saturated Fatty Acids (g): The amount of saturated fats.
Sugars (g): Total sugar content.
Sodium (mg): Salt content, measured as sodium.

The 'Positive' Components

These are the beneficial nutrients that a product receives credit points for. These points are then deducted from the negative score.

Proteins (g): The product's protein content.
Fibers (g): Dietary fiber content.
Fruits, Vegetables, Pulses & Nuts (%): The percentage of these ingredients in the product.

Calculating the Final Score

The Nutri-Score is not a simple summation. After calculating the total points for both favorable and unfavorable components, the final score is determined by subtracting the positive points from the negative points (Nutri-Score = N - P). This net score is then mapped to the five-color, letter-based scale (A to E) using a set of defined thresholds. The lower the final score, the better the rating. The algorithm has specific adjustments for different food categories, such as beverages, to ensure fair comparisons.

How the Nutri-Score is Assigned

The final numerical score translates to the a letter grade, which determines the color displayed on the packaging. Here is how the ranges typically break down:

Green 'A': Excellent nutritional quality (low score).
Light Green 'B': Good nutritional quality.
Yellow 'C': Moderate nutritional quality.
Orange 'D': Less favorable nutritional quality.
Dark Orange 'E': Low nutritional quality (high score).

Nutri-Score Limitations and Criticisms

While the Nutri-Score is praised for its simplicity and effectiveness, it is not without its critics. Some limitations include:

Oversimplification: Critics argue that reducing complex nutritional information to a single letter can be misleading. For example, a processed product might receive a better score than a minimally processed one due to the specific weightings of the algorithm, despite the latter having overall health benefits.
Portion Size: The score is calculated per 100g or 100ml, not per typical serving size. This can be misleading for products consumed in small quantities, like olive oil, which can receive a C or D despite being a healthy fat source when used in moderation.
Product Context: It's most effective for comparing products within the same category (e.g., comparing two types of breakfast cereals). Comparing products from different food groups (e.g., a breakfast cereal with a block of cheese) can be problematic and lead to misinterpretations.

Nutri-Score vs. Other Nutritional Labels


Feature	Nutri-Score	UK Traffic Light System	Keyhole (Nordic Countries)
Rating Format	5-color, A-E scale	Individual red/amber/green ratings per nutrient (e.g., fat, sugar)	A symbol identifying a healthier product choice within a category
Calculation	Single overall score balancing favorable and unfavorable components	Individual assessments for specific nutrients	Based on stricter criteria for nutrients like fat, sugar, and salt
Strength	Easy visual comparison across similar products	Clear indication of high, medium, or low content for specific nutrients	Identifies the healthier option in a category, simple to understand
Weakness	Can oversimplify overall nutritional value; might disadvantage some healthy foods	Requires more interpretation from consumers; no single overall rating	Less informative on specific nutrient levels; not a comprehensive guide

The Nutri-Score and Public Health

Since its introduction, research has shown that the Nutri-Score can positively influence consumer behavior and improve the nutritional quality of food purchases. It provides an easy-to-understand shortcut for shoppers, particularly those with low nutritional literacy, enabling them to navigate complex food labels more effectively. The system also incentivizes food manufacturers to reformulate products to achieve a better score, potentially leading to a healthier food supply.

The ongoing scientific review and updates to the Nutri-Score algorithm, such as the 2024 modifications, aim to refine its accuracy and better align it with current dietary guidelines. While it's a powerful tool, it should be used in conjunction with a broader understanding of a balanced diet and dietary recommendations from reputable health organizations.

Conclusion

The Nutri-Score works by translating complex nutritional data into a straightforward, color-coded label based on a science-backed algorithm. It effectively helps consumers compare similar products and make quick, healthier choices by balancing favorable nutrients like protein and fiber against unfavorable ones like sugar and saturated fats. Despite its limitations, such as potential oversimplification and its 100g/100ml calculation base, it remains a valuable tool for encouraging better eating habits. By understanding how does the Nutri-Score work, consumers can use it to confidently navigate grocery store aisles and support a healthier lifestyle, while still considering overall dietary context and consulting full nutritional information when necessary. The continued development and widespread adoption of the Nutri-Score reinforce its importance in public health nutrition.

Frequently Asked Questions

The primary purpose of the Nutri-Score is to provide consumers with a quick, easy-to-understand summary of a product's overall nutritional quality, helping them make more informed food choices at a glance.

The ingredients and nutrients that contribute negatively to the Nutri-Score are calories (energy), saturated fatty acids, total sugars, and sodium (salt).

Favorable ingredients that receive positive points and improve the Nutri-Score include dietary fiber, protein, and the percentage of fruits, vegetables, pulses, and nuts.

No, the Nutri-Score is a voluntary labeling system. However, in countries that have adopted it, like France and Germany, companies that choose to use it must apply it consistently across all products of a registered brand.

No, the Nutri-Score is designed for comparing similar products within the same food category, like different brands of pizza or different types of olive oil. Comparing across different categories can be misleading due to the algorithm's specific weighting.

Olive oil might receive a moderate score (e.g., C or D) because the calculation is based on 100ml, which results in a high number of points for fat content. This doesn't reflect the nutritional benefits when consumed in small, recommended portions, and is a common criticism of the system.

No, the original Nutri-Score calculation primarily focuses on the balance of beneficial versus less beneficial nutrients per 100g/ml. Critics point out that it doesn't account for the degree of industrial processing, a factor increasingly considered important for health.