Context . Soft gamma repeaters ( SGRs ) and anomalous X-ray pulsars ( AXPs ) are slow rotating isolated pulsars whose energy reservoir is still matter of debate . Adopting neutron star ( NS ) fiducial parameters ; mass M = 1.4 M _ { \odot } , radius R = 10 km , and moment of inertia , I = 10 ^ { 45 } g cm ^ { 2 } , the rotational energy loss , \dot { E } _ { rot } , is lower than the observed luminosity ( dominated by the X-rays ) L _ { X } for many of the sources . Aims . We investigate the possibility that some members of this family could be canonical rotation-powered pulsars using realistic NS structure parameters instead of fiducial values . Methods . We compute the NS mass , radius , moment of inertia and angular momentum from numerical integration of the axisymmetric general relativistic equations of equilibrium . We then compute the entire range of allowed values of the rotational energy loss , \dot { E } _ { rot } , for the observed values of rotation period P and spin-down rate \dot { P } . We also estimate the surface magnetic field using a general relativistic model of a rotating magnetic dipole . Results . We show that realistic NS parameters lowers the estimated value of the magnetic field and radiation efficiency , L _ { X } / \dot { E } _ { rot } , with respect to estimates based on fiducial NS parameters . We show that nine SGRs/AXPs can be described as canonical pulsars driven by the NS rotational energy , for L _ { X } computed in the soft ( 2–10 keV ) X-ray band . We compute the range of NS masses for which L _ { X } / \dot { E } _ { rot } < 1 . We discuss the observed hard X-ray emission in three sources of the group of nine potentially rotation-powered NSs . This additional hard X-ray component dominates over the soft one leading to L _ { X } / \dot { E } _ { rot } > 1 in two of them . Conclusions . We show that 9 SGRs/AXPs can be rotation-powered NSs if we analyze their X-ray luminosity in the soft 2–10 keV band . Interestingly , four of them show radio emission and six have been associated with supernova remnants ( including Swift J1834.9-0846 the first SGR observed with a surrounding wind nebula ) . These observations give additional support to our results of a natural explanation of these sources in terms of ordinary pulsars . Including the hard X-ray emission observed in three sources of the group of potential rotation-powered NSs , this number of sources with L _ { X } / \dot { E } _ { rot } < 1 becomes seven . It remains open to verification 1 ) the accuracy of the estimated distances and 2 ) the possible contribution of the associated supernova remnants to the hard X-ray emission .