We have directly compared the values of the magnetic moment obtained from x-ray magnetic circular dichroism (XMCD) measurements with those obtained from polarized neutron reflection (PNR) measurements on strained Ni films grown on Cu(001)/Si(001). The PNR measurements show that the absolute magnetic moments differ from that of bulk Ni. We find agreement within experimental errors between the two magnetometry measurements, confirming that the XMCD sum rules are applicable to this strained low-symmetric system.