This free mortgage affordability calculator shows exactly how much house you can afford based on your gross income, existing monthly debts, down payment, interest rate, and estimated taxes and insurance. Using the lender-standard 28/36 rule, this home affordability calculator applies both the front-end and back-end debt-to-income limits and returns the lower, safer result — the same method mortgage lenders use when reviewing applications. Get your number before you speak to a bank, before you tour homes, and before you fall in love with a property that may be outside your budget.

This mortgage affordability calculator also shows which of the two ratio limits is capping your budget — an insight that tells you exactly what to fix (income vs debt) to qualify for more house if needed.

What Is a Mortgage Affordability Calculator?

A mortgage affordability calculator is a home buying planning tool that works backwards from your financial profile to determine the maximum home price you can responsibly purchase. Unlike a standard mortgage payment calculator — which takes a loan amount and calculates the monthly payment — this home affordability calculator solves for the loan amount itself, then adds your down payment to show the total purchase price your income and debts support.

This online mortgage affordability calculator uses debt-to-income (DTI) ratios — the same framework used by Fannie Mae, FHA, VA, and conventional lenders when underwriting mortgage applications. As the Consumer Financial Protection Bureau confirms, lenders use DTI as a primary measure of mortgage affordability because it directly measures whether your income can comfortably support the proposed monthly obligation alongside existing debts.

How to Use This Mortgage Affordability Calculator

1. Gross annual income — your total household income before tax. Use combined income for joint applications.
2. Existing monthly debt payments — all current minimum monthly obligations: car loans, student loans, credit card minimums, personal loans. Do not include current rent.
3. Down payment — the cash amount you plan to put toward the purchase.
4. Interest rate (%) — use a current 30-year fixed rate estimate. Check your lender or a rate comparison site for today’s rates.
5. Loan term — 30 years is the standard; 15-year loans have higher payments but significantly lower total interest.
6. Monthly tax + insurance — estimate property tax and homeowners insurance combined. $200–$500/month is typical for many markets.
7. Click Calculate Affordability — maximum home price, monthly payment, loan amount, and principal-and-interest breakdown appear instantly.

What Percentage of Income Should Your Mortgage Be? The 28/36 Rule

The most important question this mortgage affordability calculator answers is: what percentage of income should your mortgage be? The lender-standard answer is the 28/36 rule, a two-part debt-to-income guideline:

• 28% front-end ratio — your total monthly housing payment (principal, interest, property taxes, and homeowners insurance — called PITI) should not exceed 28% of your gross monthly income.
• 36% back-end ratio — all monthly debt payments combined, including the new mortgage, should not exceed 36% of gross monthly income.

How much should your mortgage be of your income? The 28% front-end guideline is the starting point, but how much should your house payment be when you have existing debts? The back-end 36% limit accounts for those debts — which is why existing car loans, student loans, and credit card minimums directly reduce how much mortgage you can add on top. This mortgage affordability calculator applies both limits and uses whichever produces the safer lower payment, exactly as a lender would.

Some lenders allow higher DTI ratios — FHA loans, for example, can approve up to 43% back-end DTI, and some VA loan programs go higher. Adjust the results accordingly for your specific loan program.

How Much House Can I Afford? — Income-Based Examples

The most common question this mortgage afford calc answers varies by income level. Some indicative ranges at current interest rates (with 20% down, no other debts):

• How much house can I afford at $70k a year? At $70,000 gross income, the 28% front-end limit allows roughly $1,633/month for housing. After taxes and insurance, that typically supports a home in the $200,000–$240,000 range depending on rate and location.
• How much house can I afford making $80k a year? At $80,000 gross income, the front-end limit is approximately $1,867/month, typically supporting $230,000–$280,000 in purchase price at current rates.
• How much income for a $300k house? To comfortably afford a $300,000 home under the 28/36 rule, most buyers need a gross household income of at least $75,000–$90,000, assuming a standard down payment and modest existing debt.

These are estimates — use the mortgage affordability calculator above with your exact inputs for a personalised figure. Interest rates, existing debts, and down payment size significantly shift the result.

Home Loan Affordability — How Down Payment Changes Everything

Home loan affordability is not just a function of income — your down payment is an equally powerful variable. A larger down payment reduces the loan amount needed, which reduces the monthly payment, which can push your home price ceiling higher even without a higher income. Three additional benefits of a larger down payment make this lever especially important:

• Eliminates PMI — a down payment of 20% or more removes the requirement for private mortgage insurance, typically saving $100–$200/month.
• Better interest rates — lower loan-to-value ratios often qualify for marginally better mortgage rates.
• Lower home loan ratio to income — a higher down payment improves your debt-to-income ratio, making approval more likely and giving you more buying power.

House loan affordability and mortgage loan affordability are both improved by the same action: saving more before buying. Use this calculator to model different down payment scenarios — even $10,000–$20,000 more upfront often raises the affordable home price by significantly more than the down payment itself.

This Calculator vs Zillow, Bankrate, and NerdWallet Affordability Tools

You may have already checked the zillow affordability calculator, the bankrate mortgage affordability calculator, or the nerdwallet home affordability calculator. All of these tools — including this one — use the same underlying 28/36 rule framework. The results should be broadly similar because the formula is standardised. Minor differences arise from how each tool handles the standard deduction, PMI estimates, or HOA fees.

This mortgage affordability calculator is transparent about its methodology: it applies strict 28/36 limits using the inputs you provide. The Fannie Mae home buying resources explain how conventional lenders apply these same ratios in underwriting. For a VA home loan affordability calculator result, the key difference is that VA loans do not require a down payment and use a residual income test alongside DTI — adjust the down payment field to zero and use a VA-current interest rate for the closest estimate.

House Affordability — Hidden Costs That Change Your Real Budget

House affordability is not just about the mortgage payment. A budget mortgage that ignores the full cost of ownership can leave buyers financially strained within the first year. The complete cost of owning includes:

• Property taxes — vary widely by state and municipality. In high-tax states, this alone can add $400–$800/month to housing costs.
• Homeowners insurance — required by all lenders, typically $100–$200/month.
• Maintenance and repairs — financial planners recommend budgeting 1% of home value annually ($200/month on a $240,000 home).
• HOA fees — condos and many suburban communities charge $150–$500/month.
• Closing costs — typically 2–5% of the purchase price, required at closing.
• Higher utilities — a larger home typically costs more to heat, cool, and maintain than a rental.

For all home financing planning, pair this mortgage affordability calculator with our loan calculator to model the exact monthly payment on any loan amount, and our savings goal calculator to plan the timeline for building your down payment. Browse our complete free financial tools hub for all home buying and personal finance planning tools.

Frequently Asked Questions