The first general rule is that your monthly housing expenses/cost cannot be more than 32% of your gross household income. The housing costs include monthly mortgage payment (principle and taxes), taxes, and heating cost, P.I.T.H. Lenders would add up these figures and work out what percentage of your income they represent. This figure is known as Gross Debt Service, GDS. Use table below to determine your GDS ratio.

 

The second general rule is that all of your monthly liability/debt load should not exceed more than 40% of your gross monthly income. This includes your P.I.T.H and any other debts, i.e. credit card payments and loan payments. Lenders will sum up these debts to figure out what percentage of your income they represent. This ratio is called Total Debt Ratio, TDS. Use table below to calculate your TDS ratio.