TDSR(Total debt service ratio)=(payment of principal and interest on mortgage+property tax +heating costs+50% of condominium fees+payments on other personal loan)/grss income. TDSR guidelines Currently range ! \3 X9 R/ ~8 K" F6 X7 zfrom 35% to 42% of gross income. + L8 W% O7 @$ u! E& |( g1 jGDSR(gross debt service ratio)=(payment of principal and interest on mortgage+property taxes+heating costs+50% of condominium fees)/gross income.