We have carried out a coordinated experimental and theoretical study of single-electron traps based on submicron metallic (aluminum) islands and Al/AlOx/Al tunnel junctions. The results of geometrical modeling using a modified version of MIT’sFASTCAPwere used as input data for the general-purpose single-electron circuit simulatorMOSES. The analysis indicates reasonable quantitative agreement between theory and experiment for those trap characteristics which are not affected by random offset charges. The observed differences (ranging from a few to fifty percent) can be readily explained by the uncertainty in the exact geometry of the experimental nanostructures. ©1997 American Institute of Physics.