Aim <p>Consumers need guidance to distinguish between healthy and unhealthy foods to reduce the risk of diet-related diseases. The Nutri-Score can be an effective prompt that influences dietary choices by highlighting healthy options. The label’s effectiveness depends on how well consumers understand it. This study addresses a research gap by examining consumers’ <i>conceptual</i> understanding of the Nutri-Score and comparing it with their <i>objective</i> and <i>subjective</i> understanding of the label.</p> Subject and methods <p>A quantitative online survey was conducted with 156 German consumers.</p> Results <p>The results reveal insights into how well consumers understand the Nutri-Score, highlighting areas requiring further attention. The average level of objective understanding of the Nutri-Score was 84.7%, the level of subjective understanding was 69.3%, and the level of conceptual understanding was 62.5%. The three types of understanding did not correlate with each other. In terms of conceptual understanding, knowledge gaps were related to the interpretation of colors, reference values, and the impact of salt and sweeteners on the Nutri-Score calculation.</p> Conclusion <p>Different forms of assessing understanding of the Nutri-Score should be considered in research. Since significant knowledge gaps exist in consumers’ conceptual understanding, an information campaign is required to promote the correct use of the Nutri-Score.</p>