How this affordability calculator works
Lenders look at two debt-to-income (DTI) ratios. The front-end ratio compares your total housing payment with your gross monthly income; a common ceiling is 28%. The back-end ratio adds every other monthly debt payment (car loans, student loans, minimum card payments, support) and compares the total with income; a common ceiling is 36%. Your monthly housing budget is whichever limit is lower.
The calculator then searches for the highest home price whose full payment fits that budget. The payment includes principal and interest from the standard amortization formula, property tax as a percentage of the price, homeowners insurance, HOA dues, and private mortgage insurance (PMI) whenever the down payment is under 20% of the price. Because tax and PMI grow with the price, the answer is found by solving the whole payment rather than just principal and interest.
Payment(price) = P&I(price โ down) + price ร tax%/12 + insurance/12 + HOA + PMI
Worked example
Take a household earning $90,000 a year with $450 of monthly debts and $30,000 saved for the down payment, at an example 6.5% rate on a 30-year loan with 1.1% property tax and $1,800 of yearly insurance. Monthly income is $7,500. The housing limit is $2,100 and the total-debt limit is $2,250, so the budget is $2,100. The highest price that fits is about $281,175: a $251,175 loan costing $1,588 a month in principal and interest, plus $258 tax, $150 insurance and $105 PMI.
By salary
Worked tables for common incomes, each with rates and debt levels side by side:
- How much house can I afford on $40k a year?
- How much house can I afford on $50k a year?
- How much house can I afford on $60k a year?
- How much house can I afford on $70k a year?
- How much house can I afford on $75k a year?
- How much house can I afford on $80k a year?
- How much house can I afford on $90k a year?
- How much house can I afford on $100k a year?
- How much house can I afford on $110k a year?
- How much house can I afford on $120k a year?
- How much house can I afford on $125k a year?
- How much house can I afford on $130k a year?
- How much house can I afford on $140k a year?
- How much house can I afford on $150k a year?
- How much house can I afford on $200k a year?
- How much house can I afford on $250k a year?
- How much house can I afford on $300k a year?
What the number does not include
- Cash to close. Closing costs and moving costs come out of savings too. If your savings must cover both, lower the down payment field by your expected closing costs.
- Reserves. Many lenders want a few months of payments left in the bank after closing.
- Your own budget. DTI uses gross income and ignores childcare, retirement saving and commuting. Qualifying for a payment is not the same as being comfortable with it; test a 25% housing ratio to see a more conservative figure.
- Loan program rules. FHA, VA and USDA loans have their own mortgage insurance or funding fees and DTI limits.
Ways to raise what you can afford
Paying off a small debt can move the back-end ratio more than a raise would: removing a $300 car payment frees $300 a month of budget when the back-end ratio is the one that binds. A larger down payment, a lower rate from buying discount points, or a home with lower taxes or no HOA all raise the price that fits. Before shopping, compare the payment on a specific house with the mortgage calculator, and check whether buying beats renting over your time frame with the rent vs buy calculator. The 28/36 rule guide explains the ratios in more depth.