Mortgage Affordability
Calculator
Results
- Available mortgage payment
- $3,100.00
- Maximum modeled loan
- $530,286.15
- Binding debt-service constraint
- gds_tds
Comparison
| Scenario | Available mortgage payment |
|---|---|
| Gross debt service | $3,100.00 |
| Total debt service | $3,100.00 |
Formula
L = min(I × GDS − H, I × TDS − D − H) × [1 − (1+r)^−n] ÷ r- I
- 10000.00
- GDS
- 39
- TDS
- 44
- D
- 500.00
- H
- 800.00
- r
- 0.00416667
- n
- 300
= 530286.15
Note
This ratio scenario is not a lender approval and does not include every qualification rule or stress test.
More in Real estate
See all →Frequently asked questions
How does the calculator decide the maximum home price I can afford?+
It typically applies debt-to-income guidelines — commonly capping total housing costs around 28% of gross monthly income and total debts (including the mortgage) around 36% to 43% — then works backward from those limits to a maximum loan and home price. Your actual approval also depends on credit score, reserves, and lender-specific overlays.
Why does affordability change so much when I add my other debts?+
Lenders qualify you based on total debt-to-income ratio, not just housing costs, so car loans, student loans, and credit card minimums all reduce the room left for a mortgage payment. Even moderate other debt can significantly lower your maximum affordable home price.
Is the 'affordable' amount the calculator shows what I should actually spend?+
Not necessarily — it reflects what a lender is likely to approve, which is a ceiling based on income ratios, not a personalized budget that accounts for your savings goals, lifestyle spending, or risk tolerance. Many financial planners recommend staying comfortably below the maximum approved amount.
Why does my affordability number change so much with the interest rate I enter?+
A higher interest rate increases the monthly cost of every dollar borrowed, so to keep the payment within the same income-based limit, the maximum loan amount — and therefore home price — must shrink. This is why affordability estimates need to be recalculated whenever rates move meaningfully.
Does the calculator account for property taxes and insurance in my area?+
It uses your entered or estimated property tax rate and insurance cost, which vary widely by location, so results are only as accurate as those inputs. Using a national average instead of your actual local rates can meaningfully overstate or understate what you can afford.