We assess the incidence of numeracy skills mismatch in five countries: Belgium, Chile, Italy, Netherlands, and the United States of America. To do this, we make use of a new approach (Brun-Schamme & Rey, 2021), namely by identifying someone as being mismatched if the score for numeracy skills is outside the interval [median – SD , median + SD]. We make use of the PIAAC dataset, collected by the OECD, a survey that measures adults’ proficiency in numeracy among other type of skills. We find that 14% of the workers are over-skilled, whereas 16% are under-skilled. Being over-skilled is more likely for men, younger age-groups, having a high level of education, using numeracy skills often at work, and having studied science, mathematics, and engineering.