SamCalculator

House Affordability Calculator

Estimate how much house you can realistically afford based on your income, debt, mortgage rate, and monthly budget.

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Gross (pre-tax)

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Car, student, credit cards

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20%+ eliminates PMI

yrs

Typical: 10, 15, 20, or 30 years

%

Current 30-yr fixed avg ~6.5–7.5%

Monthly Housing Costs

/yr
%
/mo
$
/mo
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/mo
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Blank = 0.5%/yr auto

Loan Type

US State (optional — auto-fills tax & insurance)

How Lenders Decide How Much You Can Borrow

When you apply for a mortgage, underwriters don't simply glance at your paycheck — they run two separate math tests that reveal what fraction of your income is already committed to existing obligations. Passing both gates determines your maximum loan approval.

F

Front-End Ratio — The Housing-Only Test

Banks call this the housing ratio because it isolates one category alone: every dollar you'll owe monthly for shelter. That means principal repayment, interest charges, property taxes, homeowner's insurance, HOA dues, and PMI if your down payment is under 20%. Divide that total by your gross monthly income and you have the front-end percentage.

Front-End DTI Formula

Front-End DTI=
Monthly Housing CostsMonthly Gross Income
× 100%

Applies to: Conventional loans cap this at 28%. FHA allows up to 31%. VA loans skip the front-end check entirely and only use the back-end ratio.

B

Back-End Ratio — The Full Debt Picture

The back-end check stacks every recurring monthly obligation on top of projected housing costs. Car payments, student loan minimums, credit card minimums, and personal loans all count. Divide the combined total by gross monthly income and you get the back-end DTI — the number every mortgage lender actually makes their lending decision on.

Back-End DTI Formula

Back-End DTI=
Housing Costs + All Monthly DebtsMonthly Gross Income
× 100%

The harder gate: A 36% back-end target means for every $5,000 in monthly gross income, no more than $1,800 can leave for any debt combined. This calculator uses back-end DTI as its primary constraint.

Inside the Four Loan Programs

CONVENTIONALFront-End ≤ 28% · Back-End ≤ 36%

Conventional — The 28/36 Standard

Conventional mortgages aren't government-insured. They're bought and sold by Fannie Mae and Freddie Mac under a defined set of underwriting standards. The 28/36 guideline has governed these loans for decades — cross above 36% on the back end and most lenders won't approve without exceptional compensating factors like a pristine credit file or substantial cash reserves.

28%
Max front-end DTI
Housing costs only
36%
Max back-end DTI
All monthly debts

Putting 20% or more down on a conventional loan eliminates PMI immediately — that $100–$300 monthly saving can shift your affordable price range by tens of thousands of dollars. Strong borrowers sometimes get approved up to 43–45% back-end DTI, but lenders treat that as the outer edge, not the target.

FHAFront-End ≤ 31% · Back-End ≤ 43%

FHA — Built for Buyers Who Need More Flexibility

The Federal Housing Administration doesn't lend money — it insures lenders against borrower default, which lets them loosen their standards. The tradeoff is mortgage insurance: an upfront premium at closing plus an annual premium baked into monthly payments, often for the life of the loan. What FHA gives in return: a lower credit score floor, a 3.5% minimum down payment, and more DTI room than conventional products.

31%
Max front-end DTI
3% more than conventional
43%
Max back-end DTI
7% more than conventional
✓580+ credit score qualifies for 3.5% down payment
✓Practical path to ownership for buyers with thin credit histories
⚠1.75% upfront mortgage insurance premium due at closing
⚠Annual MIP stays for the life of the loan when down payment is under 10%
VANo Front-End Limit · Back-End ≤ 41%

VA — The Most Powerful Mortgage Benefit in America

The VA Loan Guaranty program rewards military service with terms unavailable anywhere else on the market. Eligible veterans, active-duty members, and qualifying surviving spouses can buy with zero down, no monthly mortgage insurance, and rates that routinely undercut the conventional market. VA uses a single back-end gate at 41% — no separate front-end check — plus a residual income analysis that verifies enough cash remains after all obligations, not just that ratios look clean on paper.

0%
Down payment required
No minimum down payment
41%
Max back-end DTI
No front-end requirement
✓No PMI — saves $100–$300/month compared to low-down conventional loans
✓Interest rates typically below the conventional market benchmark
⚠VA funding fee of 1.25%–3.3% of loan amount (waived for certain disabled veterans)
⚠Eligibility is limited to qualifying service members, veterans, and surviving spouses
CUSTOM DTISet your own limit

Custom DTI — Dial In Your Own Numbers

Every borrower's situation has wrinkles. Your lender might use non-standard limits based on portfolio products, state programs, or your specific financial profile. Custom mode lets you enter front-end and back-end limits manually so results reflect your actual approval window rather than a generic guideline. The calculator caps input at 50% — the point where DTI exceeds risk thresholds accepted by virtually any mortgage lender.

Conservative20–28% back-end — more headroom to absorb job loss or unexpected expenses
Moderate29–36% back-end — standard lender comfort zone, widely approved
Aggressive37–50% back-end — maximum stretch; budget becomes tight with little safety net

When in doubt, start with the Conventional 28/36 guideline as a conservative baseline. Most buyers do best aiming for the lower end of what their lender will approve — a tight DTI means a tight month, every month, for the life of the loan.

When the Numbers Say No: Closing the Gap

Being priced out today isn't a permanent condition. The home budget formula has only a handful of moving parts, and improving even two of them can shift the outcome meaningfully.

1

Attack High-Interest Consumer Debt First

Credit card minimums feed directly into your back-end DTI. A $400 minimum eliminated from your monthly obligations is roughly equivalent to qualifying for $60,000–$70,000 more in home value at current rates. Prioritize high-rate balances before saving for a down payment.

2

Build Your Credit Before Applying

Credit scores don't just determine whether you qualify — they set your interest rate tier. At a $350,000 loan, the gap between a 680 and 760 score can mean 0.75–1.0% difference in rate, adding $100+ to your monthly payment and tens of thousands in total interest over the loan.

3

Grow Your Down Payment Strategically

Each additional percent you put down lowers loan amount, reduces monthly cost, and narrows the loan-to-value ratio that triggers PMI. Hitting 20% is a meaningful threshold. Reaching 25% or 30% typically unlocks the best rate tiers and signals financial strength to underwriters.

4

Use Cash Reserves as a Negotiating Asset

When DTI hovers near the limit, verified savings can tip an underwriter's decision. Having six months of housing costs sitting in a documented account demonstrates you can absorb an income disruption — that resilience is something lenders actively look for in borderline files.

5

Strengthen Your Income Story

Lenders care about both the size and stability of income. A consistent history of rising earnings — through promotions, certifications, or a secondary income source with a two-year track record — expands your qualifying range and builds lender confidence at the same time.

6

Expand Your Geographic Search

With remote work decoupling salary from location, the same income now buys meaningfully more home in many markets outside major metros. Running your numbers across different regions can reveal options that simply weren't available when your job required a specific commute.

Renting deliberately can be the smartest move.

A year or two of intentional preparation — paying down debt, growing savings, and strengthening your credit — can be the difference between barely qualifying at a high rate and walking into a lender's office with real leverage. Time in a rental isn't wasted; it's preparation.

Frequently Asked Questions

On a $60,000 annual salary ($5,000/month), using the 28% front-end DTI rule, you can spend up to $1,400/month on housing. At a 7% interest rate for 30 years with 10% down, this translates to roughly a $185,000–$200,000 home. With lower debt and a higher down payment, you could qualify for more.

A front-end DTI (housing costs only) of 28% or below is considered safe by most lenders. A back-end DTI (total debts including housing) of 36% or below is ideal. Conventional lenders may approve up to 43–45%, and FHA allows up to 50% with compensating factors. Lower is always better.

No. A 20% down payment is not required but eliminates PMI and often results in better rates. FHA loans allow 3.5% down, VA and USDA loans allow 0% down, and conventional loans go as low as 3–5% down. The key trade-off is PMI cost vs. time to save a larger down payment.

Interest rate is one of the most powerful factors in affordability. A 1% rate increase on a $300,000 loan reduces your buying power by roughly $35,000–$40,000. Going from 4% to 7% on a 30-year $300,000 mortgage increases your monthly payment by about $600. Always shop multiple lenders to compare rates.

Private Mortgage Insurance (PMI) is required on conventional loans when your down payment is less than 20%. PMI typically costs 0.5%–1.5% of your loan amount per year (e.g., $125–$375/month on a $300,000 loan). Avoid PMI by: putting 20%+ down, getting a piggyback loan, or choosing an FHA/VA/USDA loan. PMI automatically cancels once you reach 22% equity.

The 28/36 rule is a widely used guideline: spend no more than 28% of gross monthly income on housing (front-end DTI), and no more than 36% on all debt combined (back-end DTI). For example, with $6,000/month income: max housing = $1,680, max total debt = $2,160. This rule helps ensure your budget remains sustainable long-term.

A 15-year mortgage has higher monthly payments but saves tens of thousands in interest and builds equity faster. A 30-year mortgage has lower monthly payments, giving more cash flow flexibility. Choose 15-year if you can comfortably afford the higher payment. Choose 30-year if you need lower payments or want to invest the difference.

Closing costs are fees paid at settlement, typically 2%–5% of the purchase price. On a $300,000 home, expect $6,000–$15,000. They include lender fees, title insurance, appraisal, attorney fees, and prepaid taxes. Always ask lenders for a Loan Estimate to compare closing costs before committing.

Yes, but student loans count toward your back-end DTI. Lenders typically use 0.5%–1% of your student loan balance as the monthly payment for DTI calculation, even if you're on income-driven repayment. The higher your student debt, the less house you can afford. Reducing your balance or enrolling in income-driven repayment can help.

The ideal down payment depends on your goals. 20% is the benchmark to avoid PMI and get the best rates. 10–15% is a good middle ground. 3–5% gets you into a home sooner but means PMI and less equity. As a rule of thumb: save 3% for the down payment, 2–5% for closing costs, and 3–6 months of expenses as an emergency fund.

Conventional loans require 620+ credit score, 3–20% down, and DTI under 43–45%. FHA loans allow 580+ credit score and 3.5% down, DTI up to 50%, but require mortgage insurance for the life of the loan. VA loans are for eligible veterans — no down payment, no PMI, competitive rates, DTI typically under 41%.

HOA fees count toward your front-end DTI, directly reducing how much house you can afford. A $300/month HOA is equivalent to adding about $60,000 to the home price in terms of budget impact. Always factor HOA into your calculations and investigate the HOA's financial health and any upcoming special assessments before buying.

Your rate is affected by: credit score (higher = lower rate), down payment percentage (more = lower rate), loan type and term, current market rates, property location, loan size (jumbo loans cost more), and your debt-to-income ratio. A 720+ credit score with 20% down typically qualifies you for the best available rates.

Use the calculator first to understand your ballpark budget, then get pre-approved to know your actual limits. Pre-approval involves a credit check, income verification, and asset review — giving you a firm number. Our calculator uses standard DTI guidelines, but lenders may adjust based on your credit score, assets, employment history, and specific loan product.

Beyond the purchase price, budget for: closing costs (2–5%), moving expenses ($1,000–$5,000), immediate repairs ($2,000–$10,000), home inspection ($300–$500), ongoing maintenance (1–2% of home value per year), property taxes, HOA fees, and a 3–6 month emergency fund. Total first-year costs are often $15,000–$30,000 beyond the down payment.

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