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 # ~% a3 t, W9 i$ g5 c' jfrom 35% to 42% of gross income. 5 k5 f6 m% j$ Z4 A+ F" f, YGDSR(gross debt service ratio)=(payment of principal and interest on mortgage+property taxes+heating costs+50% of condominium fees)/gross income.