🏦 Mortgage Affordability Calculator

The 28/36 Rule: How Lenders Decide What You Can Borrow

Most mortgage lenders in the United States evaluate borrowers using the 28/36 rule, a guideline endorsed by Fannie Mae and Freddie Mac. The rule sets two debt-to-income thresholds that determine your maximum loan size.

Front-End Ratio (28%)

Your total monthly housing payment — principal, interest, property taxes, homeowners insurance, PMI, and HOA dues — should not exceed 28% of your gross monthly income. On the 2024 national median household income of $83,730, that ceiling is roughly $1,954 per month.

Back-End Ratio (36%)

All recurring monthly debt obligations combined — housing costs plus car loans, student loans, credit-card minimums, child support — should stay below 36% of gross income. With the same median income, the total debt ceiling is about $2,512 per month. If you carry $400 in existing debts, only $2,112 remains for housing.

When Lenders Flex the Numbers

FHA-insured loans allow ratios up to 31/43, and some conventional lenders approve borrowers with a back-end DTI as high as 50% when compensating factors exist — strong credit scores, large cash reserves, or documented income growth. VA loans have no official front-end cap at all. However, stretching beyond 36% tightens your monthly budget and leaves less room for emergencies. This calculator flags ratios above 36% as "Stretched" and above 43% as "Risky."

How the Calculator Finds Your Maximum Home Price

This tool works backward from your income and debt limits to find the highest purchase price that keeps you within lending guidelines. The process runs in five steps:

1. It computes your maximum allowable monthly housing payment at the chosen front-end ratio (default 28%).
2. It computes the maximum total monthly debt payment at the back-end ratio (default 36%) and subtracts your existing debts.
3. It takes the lower of those two amounts as your housing budget.
4. It subtracts fixed monthly costs — insurance and HOA — from that budget.
5. Using the remaining amount, it solves the amortization formula in reverse for the home price that produces a monthly principal-interest-tax-PMI payment within your budget.

The result is rounded down to the nearest $1,000 for a conservative estimate. Five what-if scenarios then show how affordability shifts with different interest rates, down payments, and income levels.

Mortgage Rates and Affordability in 2026

As of April 2026, the Freddie Mac Primary Mortgage Market Survey places the 30-year fixed rate at 6.37–6.46%, slightly below the 6.64% averaged a year earlier. While any decline helps, today's rates remain roughly double the sub-3% lows of 2020–2021.

What Each Percentage Point Costs You

Every one-percentage-point rise in the mortgage rate reduces purchasing power by approximately 10%. A household earning $83,730 with minimal debts can afford roughly $340,000 at a 5.5% rate. At 7.5%, that same household drops to about $275,000 — a gap of $65,000. The scenario analysis built into our results quantifies this for your exact inputs.

Rate-Lock Strategy

Rates have been volatile since 2022. When you find a favorable quote, most lenders offer a 30- to 60-day rate lock at no cost. Longer locks (90 days or more) may carry a small fee but protect against sudden spikes during the closing process.

Property Taxes and Insurance: The Hidden Affordability Squeeze

Principal and interest are the line items buyers focus on, but property taxes and homeowners insurance often determine whether a purchase is truly affordable.

Property Tax Variation Across States

Effective property-tax rates range from 0.28% in Hawaii to 2.42% in New Jersey, according to the Tax Foundation. On a $400,000 home, that difference alone is $1,120 versus $9,680 per year — nearly $713 more each month in New Jersey than in Hawaii. Our New Jersey and Ohio affordability calculators pre-fill the local rate so you see realistic numbers immediately.

Homeowners Insurance Is Rising Fast

The national average homeowners premium reached approximately $2,543 per year in 2025, but costs vary wildly by state. Florida leads at over $7,100 annually, followed by Louisiana and Nebraska above $6,000. Hawaii is the cheapest at $659. Insurify projects an additional 4% increase nationwide in 2026, with California (+16%), Nebraska (+13%), and New Mexico (+11%) facing the steepest hikes. For buyers in high-premium states, insurance can reduce affordable purchase price by $30,000–$50,000 compared to a low-cost state.

Down Payments and First-Time Buyer Programs

The down payment determines your loan size, whether you pay PMI, and how much cash you need at closing. It is often the biggest barrier for first-time buyers.

How Down Payment Size Affects Affordability

Putting 20% down on a $400,000 home means $80,000 upfront but eliminates PMI (typically 0.3%–1.5% of the loan annually). At 10% down, you need only $40,000 but add roughly $150–$200 per month in PMI until you reach 20% equity. FHA loans allow as little as 3.5% down — just $14,000 on that same home — but require mortgage insurance for the life of the loan unless you refinance.

State Housing Finance Agency Programs

Every state operates a housing finance agency (HFA) that offers down-payment assistance to qualifying buyers. Common structures include forgivable second mortgages, zero-interest deferred loans, and outright grants of $5,000–$15,000. Eligibility usually requires income below the area median, first-time buyer status (no homeownership in the past three years), and completion of a HUD-approved homebuyer education course. Use our state-specific calculators — such as Texas, California, or Florida — to model affordability with your state's tax and insurance rates built in.

Strategies to Expand Your Purchasing Power

• Pay down revolving debt first. Every $200 you eliminate from monthly obligations can add $25,000–$30,000 to your affordable home price.
• Add a co-borrower. A spouse or partner's income is added to yours, often increasing purchasing power by 40–60%.
• Target a credit score above 740. Borrowers with scores above 740 typically receive rates 0.25%–0.50% below those offered to borrowers in the 680–719 range, translating to $15,000–$25,000 in additional affordability.
• Explore lower-tax jurisdictions. Property-tax rates can vary significantly even within a single metro area. A home in a county with a 0.8% rate is more affordable than the same home at 1.4%.
• Consider a 30-year term. Monthly payments on a 30-year loan are roughly 30% lower than a 15-year, though total interest paid is higher.
• Lock your rate early. In a volatile rate environment, a 30-day lock costs nothing and protects your budget during the closing timeline.

Closing Costs: The Expense Beyond the Down Payment

Down payment is not the only upfront cash you need. Closing costs — including lender fees, title insurance, appraisal, escrow deposits, and recording fees — typically add 2% to 5% of the loan amount. On a $350,000 home, expect $7,000 to $17,500 on top of your down payment.

What Closing Costs Include

The largest components are origination fees (0.5–1% of the loan), title insurance ($1,000–$3,000), appraisal ($400–$700), and prepaid items like property taxes and homeowners insurance held in escrow. Government recording fees and transfer taxes vary by county and state — New York, for example, adds a mansion tax on purchases above $1 million.

Negotiating and Reducing Closing Costs

Buyers can ask the seller to cover part or all of closing costs as a concession, especially in a buyer's market. Lender credits are another option: the lender covers some costs in exchange for a slightly higher interest rate. Shopping for title insurance and comparing lender estimates using the standardized Loan Estimate form can save $1,000 or more.

Student Loans, Car Payments, and Other Debt Traps

Existing monthly obligations are the second-largest factor in affordability after income. Lenders count every recurring payment — auto loans, student loans, personal loans, credit-card minimums, child support, and alimony — toward your back-end DTI ratio.

Student Loan Calculations

For borrowers on income-driven repayment (IDR) plans, lenders can use the actual monthly payment rather than the full amortized amount. If your loans are in deferment or forbearance, most lenders use 0.5% of the total balance as the assumed monthly payment. For someone with $50,000 in deferred student debt, that adds $250 to the monthly debt calculation — enough to reduce affordable home price by $30,000 or more.

The $200 Rule of Thumb

Every $200 per month in recurring debt reduces your maximum affordable home price by roughly $25,000 to $30,000. Before house-hunting, consider whether paying off a $6,000 credit-card balance (eliminating a $200 minimum payment) would be a better use of cash than adding that amount to your down payment. In most rate environments, debt elimination yields a larger affordability gain.

Affordability by State and City

Housing costs, taxes, and insurance vary dramatically across the country. We offer dedicated calculators with local data pre-filled for these locations:

State Calculators

• California — Prop 13 caps, median above $750K
• Texas — No income tax, high property tax
• Florida — Homestead exemption, elevated insurance
• New York — High income tax, city surcharges
• Illinois — 2.08% property tax, Cook County complexity
• Ohio — Municipal income taxes, affordable housing
• Pennsylvania — Earned income tax, variable county rates
• New Jersey — Highest property taxes in the US
• Georgia — Low cost of living, Atlanta exception
• North Carolina — Research Triangle growth, moderate taxes

City Calculators

• New York City — Co-ops, city income tax, high prices
• Los Angeles — Earthquake/wildfire insurance, Mello-Roos
• San Francisco — Median above $1.3M, tech salaries
• Chicago — Transfer tax, high property tax, neighborhood spread
• Miami — Flood insurance, foreign buyer market
• Houston — No zoning, MUD taxes, sprawl
• Dallas — Property tax above 2%, rapid growth
• Austin — Tech boom pricing, homestead exemption
• Orlando — Tourism economy, hurricane insurance
• San Diego — Military housing allowance, Mello-Roos