Electric power applications of coated conductor tapes (e. g. power transmission cables, transformers, fault current limiters) are developed nowadays. Optimal design of these applications requires a realistic model of the electromagnetic behaviour of a single tape. We compare here four models that could represent the tape in electromagnetic calculations. The simplest model assumes a rectangular cross-section of superconducting layer and constant critical current density. Models that are more complex consider the critical current density depending on magnetic field and its orientation. Furthermore, one could introduce a non-uniformity of the superconducting layer across the tape width. We checked the predictive power of these models by comparing the agreement between the calculated values of magnetic field above the tape and the experimental data obtained by Hall-probe experiments. In the case of commercial coated conductor tape on non-magnetic substrate the most representative model incorporated the critical current density dependence on magnetic field as well as the assumption of worsening the layer properties towards the tape edges. The latter conclusion was confirmed by the experiment in which longitudinal strips cut from the tape were tested.