Mortgage Affordability Calculator 2026 — Free Online Tool

Q: How much gross income is needed for a $400,000 home?

Assuming a 10% down payment and a 6.85% interest rate, you typically need an annual household gross income of approximately $100,000 to $115,000 to qualify comfortably under standard DTI underwriting limits.

Q: What is the back-end DTI ratio?

The back-end DTI ratio measures your housing expenses (Principal, Interest, Taxes, Insurance, HOA) plus all other monthly recurring debts (minimum credit card payments, student loans, car financing, personal loans) against your gross monthly income.

Q: How does my down payment affect home affordability?

A larger down payment reduces the total loan amount needed, which lowers your monthly payments. Putting down 20% or more also eliminates the requirement for Private Mortgage Insurance (PMI), saving you significant monthly expenses.

Q: Is homeowners insurance mandatory for mortgage approval?

Yes. Lenders require borrowers to buy and maintain homeowners insurance to protect the asset (collateral) against fire, storms, and other physical damage.

Q: What is the front-end DTI ratio limit?

The front-end DTI ratio limit (typically capped at 28% under the 28/36 rule) measures your housing-only payment (PITI + HOA) against your gross monthly household income.

Q: Can I use rental income to qualify for a larger budget?

Yes. Lenders can count rental income from verified, documented lease agreements on investment properties, though they typically apply a 25% vacancy factor discount to the gross rents.

Q: What is the minimum down payment for conventional mortgages?

Conventional mortgages offer programs starting at a 3% down payment for first-time home buyers, while standard conventional programs require a 5% down payment.

Q: How do credit card balances impact my home buying budget?

Lenders do not use your total credit card balance when calculating DTI; instead, they count the minimum monthly payment shown on your credit report toward your monthly debts.

Q: What is the 28/36 rule in real estate underwriting?

The 28/36 rule is a classic underwriting standard suggesting that housing costs should not exceed 28% of gross income, and total debts (including housing) should not exceed 36% of gross income.

Q: Can a co-signer help me qualify for a higher price?

Yes. Adding a co-signer (such as a relative) adds their gross income to your application, which lowers the overall DTI ratio and can increase your approved loan limit.

Q: How do property taxes affect my purchasing power?

Property taxes are included in your escrow payment. A home in a high-tax state (like Texas or New Jersey) requires higher monthly payments, reducing your maximum borrowing budget.

Q: What is PMI and how much does it cost?

Private Mortgage Insurance (PMI) is required for down payments under 20%. It typically ranges from 0.3% to 1.5% of the loan amount annually, depending on credit score and down payment percentage.

Q: Do lenders require cash reserves after closing?

Yes, many conventional loans require 'reserves' — extra cash left over after your down payment and closing costs, typically equal to 2 to 6 months of mortgage payments.

Q: How does a 15-year mortgage affect my affordability budget?

A 15-year term features higher monthly payments than a 30-year term. While you pay off the home faster, it increases your DTI, which reduces the maximum home price you can qualify for.

Q: What happens if a home appraises for less than the purchase price?

Lenders base the loan size on the lower of the sales price or appraised value. If it appraises low, you must pay the difference in cash, renegotiate the price, or walk away.