Quantification of the trade effects of non-tariff measures (NTMs) has proven to be a major challenge. This paper uses a combination of gravity model estimates of sectoral trade potential, general equilibrium model results on non-tariff protection, and inventory-derived information on the pervasiveness of different types of NTMs to attempt a ranking of NTMs according to their trade impacts. The analysis is centred on the European Union, as trade within the EU is virtually barrier-free since the completion of the Single Market in 1992, while exports from the Union continue to face tariff and non-tariff barriers. This dichotomy between internal and external EU trade is exploited for the derivation of barrier-free extra-EU export potentials, which form the basis for the subsequent determination of tariff equivalents of NTMs. The results from the analysis show that the approach is, in principle, feasible and has the potential to contribute to a better understanding of the trade effects of NTMs. However, conceptional problems of obtaining consistent estimates of export potentials under free trade conditions and data limitations concerning representative information on NTMs across countries and sectors are the cause for a high degree of variability in the findings that do not make it possible at this stage to draw firm conclusions on the ranking of different types of NTMs according to their trade restrictiveness.