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 2 F" N3 [% A; w( U0 H* {from 35% to 42% of gross income. & x9 M9 a2 w) m2 Z: ]7 J; X& |$ `4 x% ZGDSR(gross debt service ratio)=(payment of principal and interest on mortgage+property taxes+heating costs+50% of condominium fees)/gross income.