Mortgage Affordability Calculator
Estimate the maximum home price you can afford using income, debts, down payment, interest, taxes, insurance, and HOA—following the 28/36 debt-to-income guideline.
Your details
Payment breakdown
Results interpretation
The calculator applies the common 28/36 debt-to-income rule: keep housing costs ≤ 28% of gross monthly income and all debt ≤ 36%. Your affordability is the lower of these two caps after accounting for taxes, insurance, and HOA. If the back-end cap limits you, lower debts or extend the term; if the front-end cap limits you, consider a lower tax area or higher down payment.
How this calculator works
Formula & steps
Monthly cap = min( income/12 × frontDTI, income/12 × backDTI − monthlyDebts ).
We solve for price P so that: PI(P − down) + P×taxRate/12 + insurance/12 + HOA ≤ cap.
P&I is computed via the mortgage payment formula: payment = L·r / (1 − (1 + r)−n) .
Because P appears in both P&I and taxes, we use a fast binary search to find the highest P that stays under the cap.
Assumptions: fixed-rate fully-amortizing loan; taxes proportional to price; insurance treated as a fixed annual amount. In practice taxes/insurance vary—treat results as a planning estimate.
How to use this calculator
- Enter your income and monthly debts.
- Add down payment, APR, and loan term.
- Include property taxes, insurance, and HOA for realism.
- Adjust DTI limits (28/36 default) if needed.
- Review the max home price and monthly breakdown.
Mortgage Affordability — FAQ
How much house can I afford?
A common guide is the 28/36 rule—keep housing ≤ 28% of gross monthly income and all debt ≤ 36%. This calculator applies those caps including taxes, insurance, and HOA.
What DTI do mortgage lenders look for?
Conventional loans often target ≤36–45% back-end DTI. This tool defaults to 28% front-end and 36% back-end for conservative planning.
Does property tax rate change my max price?
Yes. Higher tax rates increase the monthly housing cost and reduce the maximum affordable price at the same income and rate.
How does the interest rate affect affordability?
Higher APR increases the principal-and-interest payment, lowering your price. Improving credit or points can raise affordability.
Should I use 15-year or 30-year for affordability?
A 15-year term has higher payments, so it lowers price at a given DTI but saves interest. 30-year increases price but costs more interest over time.
How can I increase my buying power?
Reduce debts, raise your down payment, improve credit for a better rate, or shop lower-tax areas. All reduce monthly cost at a given price.
Mortgage Affordability: How Lenders Decide—and How to Improve Your Buying Power
Mortgage affordability calculator is the quickest way to estimate how much house you can afford before you shop. Lenders look at your debt-to-income (DTI), down payment, credit history, and the cost of the property (interest, taxes, insurance, HOA). This guide explains the rules behind affordability, how different inputs change your maximum home price, and smart ways to boost buying power without over-stretching your budget.
The common rule of thumb is the 28/36 rule. Aim for housing costs ≤ 28% of gross monthly income (front-end DTI) and total debt ≤ 36% (back-end DTI). Your cap is the lower of the two. Because taxes and insurance can vary by location, a price that works in one county may not work in another—even at the same interest rate. That’s why a calculator that includes APR, property tax rate, insurance, and HOA is more realistic than a simple multiple of income.
To increase affordability safely: pay down revolving debt (it directly raises the back-end cap); improve credit to qualify for a lower rate; expand your search to areas with lower property tax; or increase the down payment to shrink the loan. Beware of stretching with adjustable-rate mortgages—payments can rise—unless you have a clear exit plan.
Finally, affordability is not the same as comfort. Consider cash reserves, job stability, and upcoming expenses. A slightly smaller purchase can leave room for maintenance and peace of mind— things underwriters don’t score but homeowners value.