You find a home you love. The listing says $350,000. Your gut says "that feels about right." But your gut doesn't know your debt-to-income ratio β and your lender does.
Most buyers find out what they can afford after they fall in love with a home that won't qualify. This guide shows you the exact formula lenders use, so you know your real number before you start shopping.
Key Takeaways
- Lenders use the 28/36 rule: housing costs β€ 28% of gross income, total debt β€ 36%.
- Your maximum monthly payment is whichever is lower β the 28% cap or the back-end DTI cap.
- On an $80,000 salary at ~6.5% rates, most buyers can afford a home around $225,000β$240,000.
- Every $200/month in existing debt (car, student loans) cuts your buying power by ~$30,000β$33,000.
- Your credit score can shift your rate by 1β2% β that's $100β$342 more per month on a $250k loan.
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The Lender's Formula: Debt-to-Income Ratio (DTI)
DTI (Debt-to-Income Ratio) compares your monthly debt payments to your gross monthly income. It's the single most important number in mortgage qualification.
Lenders calculate two versions:
Front-End DTI = Monthly Housing Costs Γ· Gross Monthly Income
Back-End DTI = (Monthly Housing Costs + All Other Monthly Debts) Γ· Gross Monthly Income
"Monthly Housing Costs" = PITI (Principal + Interest + Taxes + Insurance + HOA)
The 28/36 Rule (standard guideline):
- Front-end DTI β€ 28% β housing costs stay under 28% of gross monthly income
- Back-end DTI β€ 36% β all debt combined stays under 36% of gross monthly income
In practice, most lenders accept back-end DTI up to 43%. FHA loans allow up to 50% with strong compensating factors. But qualifying at the limit means very little breathing room β one job change or car repair and you're stretched thin.
β² Check before you proceed
Qualifying at the maximum DTI leaves almost no financial cushion. A single unexpected expense β a car repair, a medical bill, or a month of reduced income β can make your mortgage payment feel impossible. Most financial planners recommend targeting a back-end DTI of 36% or below for real breathing room.
Not sure what your DTI is? Use our debt-to-income calculator to calculate it in seconds.
Step-by-Step: What Can You Afford on $80,000?
Starting numbers:
- Annual gross income: $80,000 β $6,667/month
- Existing monthly debts: $400 (car + student loans)
- Down payment: $40,000 (~5%)
- Credit score: 740
Step 1 β Maximum housing payment (front-end)
28% rule: $6,667 Γ 0.28 = $1,867/month max housing payment
Step 2 β Check back-end DTI
36% rule: $6,667 Γ 0.36 = $2,400 max total monthly debt Existing debts: β$400 Max housing payment (back-end): $2,000/month
The front-end rule wins at $1,867 β it's the tighter constraint.
Step 3 β Subtract taxes, insurance, and PMI
Estimated for a $230,000 home with 5% down:
Property taxes: $230,000 Γ 1.1% Γ· 12 = $211/month Homeowners insurance: $140/month PMI (5% down on $219k loan): $109/month ββββββββββββββββββββββββββββββ Non-loan costs: $460/month
Available for principal & interest: $1,867 β $460 = $1,407/month
Step 4 β Back into the maximum loan amount
At 6.5% for 30 years, a $1,407/month P&I payment supports a loan of approximately $222,000.
With 5% down on a $230,000 home, the loan is $218,500 β P&I β $1,381/month β total PITI β $1,841/month β (under $1,867 limit). For the full breakdown of how that P&I number is calculated, read How Mortgage Payments Are Calculated.
Result: approximately $225,000β$240,000 given these inputs.
Β» MORE: Use the Mortgage Calculator to see your exact P&I payment at any loan amount and rate
Affordability by Income and Rate
These estimates assume: 5% down payment, 1.1% property tax rate, $140/month insurance, no existing monthly debts, 30-year fixed mortgage.
| Annual Income | 6.0% Rate | 7.0% Rate | 8.0% Rate |
|---|---|---|---|
| $50,000 | $155,000 | $137,000 | $121,000 |
| $60,000 | $186,000 | $165,000 | $146,000 |
| $80,000 | $248,000 | $220,000 | $195,000 |
| $100,000 | $310,000 | $275,000 | $244,000 |
| $120,000 | $372,000 | $330,000 | $293,000 |
| $150,000 | $465,000 | $413,000 | $366,000 |
| $200,000 | $620,000 | $550,000 | $488,000 |
Estimates only. Adjust for local tax rates, existing debt, and actual down payment. Current 30-year rate: 6.51% as of May 21, 2026 (Freddie Mac PMMS) β your estimate falls between the 6.0% and 7.0% columns.
Each $200/month in existing debt cuts buying power by approximately $30,000β$33,000 at current rates (~6.5%).
What Banks Look At Beyond Income
Credit Score and Your Rate
Your credit score changes your interest rate β which directly changes what you can afford.
| Credit Score | Rate Estimate | Monthly P&I on $250k | Monthly Difference |
|---|---|---|---|
| 760+ | 6.50% | $1,580 | β |
| 720β759 | 6.75% | $1,622 | +$42 |
| 680β719 | 7.25% | $1,706 | +$126 |
| 640β679 | 8.00% | $1,834 | +$254 |
| 620β639 | 8.50% | $1,922 | +$342 |
Rate estimates based on Freddie Mac PMMS benchmark (May 2026). Actual lender quotes vary.
The difference between a 760 and 640 score on a $250,000 loan: $254/month β that's $91,440 over 30 years.
Down Payment and PMI
LTV (Loan-to-Value) = Loan Amount Γ· Home Value. The lower your LTV, the better your rate and the less you pay in PMI.
| Down Payment | LTV | PMI? | Notes |
|---|---|---|---|
| 3% | 97% | Yes | FHA/conventional minimum |
| 5β10% | 90β95% | Yes | PMI until 80% LTV |
| 20% | 80% | No | No PMI; best standard rate |
| 25%+ | 75% | No | Best rates for jumbo loans |
PMI typically costs 0.3%β1.5% of the loan per year. On $250,000 at 0.8%, that's $167/month added to your PITI.
β Keep in mind
PMI on conventional loans doesn't disappear on its own. Once your balance reaches 80% of the original purchase price, you must request cancellation in writing. It cancels automatically at 78% LTV β but that threshold is based on your original payment schedule, not your home's current market value.
Cash Reserves
After closing, lenders want to see 2β6 months of PITI in savings β separate from your down payment. If your PITI is $1,800/month, expect to need $3,600β$10,800 sitting in your account after closing day.
Don't forget closing costs: typically 2β5% of the purchase price, paid at closing on top of your down payment. On a $230,000 home, that's $4,600β$11,500 in fees (lender fees, title insurance, appraisal, prepaid taxes). More than 40% of first-time buyers say they were caught off guard by these costs.
Also budget for ongoing maintenance: a reliable rule of thumb is 1β2% of the home's value per year. On a $230,000 home, that's $2,300β$4,600/year ($192β$383/month) for repairs, appliances, and upkeep. This money is separate from your mortgage payment β it's the hidden cost that turns a comfortable house payment into a stretched budget.
β Important
Budget for three separate cash buckets before closing: the down payment, closing costs (2β5% of the purchase price), and 2β6 months of PITI in reserves. On a $230,000 home with 5% down, that's $11,500 down + up to $11,500 in closing costs + up to $10,800 in reserves β as much as $33,800 in total cash needed before move-in day.
Employment History
Most lenders require 2 years of continuous employment in the same field. Self-employed borrowers need 2 years of tax returns showing stable or growing income.
How Existing Debt Cuts Your Budget
Every dollar of monthly debt reduces your maximum housing payment by exactly one dollar.
| Existing Monthly Debt | Max Home Price ($80k income, ~6.5%) |
|---|---|
| $0 | ~$285,000 |
| $200 | ~$252,000 |
| $400 | ~$226,000 |
| $600 | ~$200,000 |
| $800 | ~$173,000 |
| $1,000 | ~$147,000 |
A $500/month car payment reduces your buying power by roughly $75,000β$80,000 at current rates.
Β» MORE: Calculate your exact DTI ratio and see how your existing debt affects your mortgage qualification
FHA vs. Conventional: Different Rules
Conventional Loans (Fannie Mae / Freddie Mac)
- Minimum credit score: 620 (best rates at 740+)
- Maximum back-end DTI: 45% (up to 50% with compensating factors)
- Minimum down payment: 3%
- PMI: Required below 20% down; cancels automatically at 80% LTV
FHA Loans
- Minimum credit score: 580 with 3.5% down; 500 with 10% down
- Maximum back-end DTI: 43% standard; up to 50% with strong factors
- Minimum down payment: 3.5%
- 2026 loan limits: $541,287 (most counties) to $1,249,125 (high-cost areas) β HUD
- MIP (Mortgage Insurance Premium): Required for the life of the loan if less than 10% down
FHA allows lower scores and higher DTI, but the permanent MIP makes it more expensive long-term. If you can qualify conventional, it's usually the better deal β especially once you build equity past 20%.
VA Loans (Veterans only)
- No down payment required; no PMI
- DTI: typically up to 41%
- Funding fee: 1.4%β3.6% of loan (varies by down payment and use)
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The 20% Down Payment: Worth It?
The standard advice is "put 20% down." Here's when that's right β and when it isn't.
Reasons to put less than 20% down:
- Opportunity cost β money locked in home equity earns nothing. If investments return 7%/year and PMI costs $150/month ($1,800/year), you're paying a 0.6% premium to deploy capital elsewhere.
- Home appreciation still accrues on the full value β whether you put 5% or 20% down, price gains apply to the whole home.
- Getting in sooner matters β in rising markets, waiting to save 20% costs more than the PMI would have.
Reasons to put 20% down:
- No PMI on day one β immediate savings on every payment
- Better rate β typically 0.125%β0.25% lower at 80% LTV
- Easier qualification β lower payment makes DTI math work more easily
- Buffer against price drops β more equity means less risk if the market dips
Rule of thumb: If you're confident in the market and have investments earning more than your PMI costs, less than 20% can be rational. If you're risk-averse, 20% down gives you a meaningful cushion.
Warning: Pre-Approval β What You Can Comfortably Afford
A lender will approve you for the maximum they're allowed to lend β not the maximum you should borrow. Getting approved for $400,000 when your comfortable budget is $300,000 is common, and it can lead to being "house poor" β owning a home that eats every spare dollar.
Run your own DTI math first. Decide on your comfortable monthly payment before you talk to a lender. Then use the pre-approval process as a ceiling check, not a shopping budget.
3 Ways to Increase What You Can Afford
1. Pay down existing debt before applying
Every $100/month reduction in monthly debt obligations adds roughly $14,000β$15,000 in buying power. Paying off a car loan or credit card balance before applying can move your budget meaningfully.
2. Improve your credit score before shopping
Moving from 680 to 760 can lower your rate by 0.75% or more. On a $300,000 loan, that saves $150/month β and increases your qualifying price by $20,000+. Give yourself 6β12 months to optimize before applying.
3. Shop multiple lenders
Rates vary by 0.25%β0.5% across lenders for the same borrower profile. If you shop within a 14β45 day window, all mortgage inquiries count as one hard pull on your credit. The few hours spent comparing quotes can save tens of thousands over the life of the loan.
The Bottom Line
On an $80,000 salary with no existing debt, you can afford roughly $220,000β$248,000 depending on the rate. Every $200/month in existing debt shaves $30,000β$33,000 off that ceiling. Run your own DTI math before you talk to a lender β decide on the monthly payment that fits your actual budget, then work backwards to the home price. The lender's maximum and your comfortable maximum are rarely the same number.
Common Questions
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Methodology & Sources
Home affordability calculations use the standard PMT formula for mortgage payment calculations. DTI guidelines reflect the Fannie Mae Single Family Selling Guide and FHA Single Family Housing Policy Handbook 4000.1. PMI estimates reflect a range of 0.46%β1.50% per the Consumer Financial Protection Bureau (CFPB). Property tax rates reflect the national average of approximately 1.1% per Tax Foundation (2026). FHA loan limits reflect HUD's 2026 published limits. Rate benchmarks use the Freddie Mac Primary Mortgage Market Survey (May 21, 2026: 6.51% 30-year fixed).
Sources: Fannie Mae Selling Guide, FHA Handbook 4000.1, Consumer Financial Protection Bureau (CFPB), Freddie Mac PMMS, HUD Mortgage Limits.
Disclaimer: Results are for educational and informational purposes only. FiscalCalc is not a licensed financial advisor, mortgage broker, or tax professional. Consult a qualified professional before making major financial decisions.