Ten commercially available nanoporous carbons from a range of suppliers were initially selected for our study (see Methods). Analysis of gas sorption data revealed that five of the studied carbons had very similar pore size distributions (Fig. , fig. ) and similar specific BET define surface areas (1694-1821 m 2 /g, table ), so these were selected to test whether factors beyond porosity 85 impact capacitance. Despite the similarity in pore size distributions, these five carbons exhibit significantly different capacitance values with a standard NEt4BF4 in acetonitrile (1 M) electrolyte, with values ranging from 138 F/g to 83 F/g (Fig. , fig. , fig. ). Measurements at different charging rates (fig. ), as well as the measurements with ionic liquid electrolytes (fig. ), revealed similar results, with ACS-PC and SC-1800 displaying the highest capacitances and PW-400 90 displaying the smallest capacitance. Together, these findings suggest that factors beyond pore size and specific surface area impact capacitance.