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 . b8 H4 r3 U6 k7 Q6 U; Mfrom 35% to 42% of gross income. 0 o( W: S& f9 T" `/ |GDSR(gross debt service ratio)=(payment of principal and interest on mortgage+property taxes+heating costs+50% of condominium fees)/gross income.