Loan Qualifier Calculator
Lenders do not qualify you on the price of the house. They qualify you on a monthly payment, using two ratios: housing at or under 28% of gross monthly income, and housing plus every other monthly debt at or under 36%. This loan qualifier calculator runs both caps on your income and debts, shows which one binds, and converts the winning payment into the largest loan and home price it supports.
Estimate using the conventional 28/36 guideline on principal and interest. Taxes, insurance, HOA, and PMI are not included; a lender’s pre-approval is the final word.
Quick Answer
On $120,000 of gross income with $500 a month of debts, $40,000 down, at 6.5% over 30 years, the 28% front-end cap allows a $2,800 monthly housing payment, which beats the 36% back-end cap of $3,100, so the front-end binds. That payment supports a maximum loan of $442,990.29 and a maximum home price of $482,990.29, at a 28.0% front-end ratio and a 33.0% back-end ratio. The calculator above is pre-filled with this exact case.
Key takeaways
- Two caps, one winner: 28% of gross monthly income for housing, 36% for housing plus all other debts. The lower cap is your payment, and the tool names which one bound you.
- Debt only starts costing you home price after it passes the 8-point gap between the caps: $800 a month on a $120,000 income. Past that point, every $500 a month of debt removes $79,105.41 of loan at 6.5% over 30 years.
- 28/36 is the conservative end of real underwriting. Fannie Mae automated approvals can reach a 50% total ratio and FHA runs 31/43, so a lender may approve more than this page shows.
- The result is principal and interest only. Taxes, insurance, HOA dues and PMI sit on top of the payment in a real lender ratio, so the price you can truly carry is lower.
- Quick Answer
- How to use the loan qualifier calculator
- The 28/36 math, step by step
- Worked example: $120,000 income, $500 of debts, 6.5% for 30 years
- What each income supports at 6.5%
- How 28/36 compares with the ratios lenders actually use
- The honest gap: this tool prices principal and interest only
- Five moves that raise your qualifying price
- What competing calculators miss
- Frequently asked questions
How to use the loan qualifier calculator
Enter your gross income, your recurring monthly debts, your down payment, the rate and the term, then click Calculate. Results stay hidden until you do.
- Annual gross income: pre-tax income for everyone on the loan. Lenders verify it from pay stubs and tax returns, and the Consumer Financial Protection Bureau’s Appendix Q standards set out which income counts and how it is documented.
- Monthly debts: payments, not balances. Card minimums, car and student loan payments, support obligations. Leaving the field blank counts as $0 in this tool, so blank means debt-free, not unknown.
- Down payment: added at the very end. It raises the price dollar for dollar but does nothing to the payment cap, which is why two buyers with the same income and debts qualify for the same loan and different prices.
- Rate and term: together they set the annuity factor. Change nothing else and drop the term from 30 to 15 years, and the worked example’s loan falls by $121,560.34.
- Read the binding constraint line: it tells you which lever to pull. Front-end bound means income, rate or term is your problem. Back-end bound means debts are, and the fix is paying one down.
For the stand-alone ratio on an existing set of debts, the debt-to-income ratio calculator works the percentage itself out in full. Once you have a target payment from this page, the mortgage payment calculator breaks a payment of that size into principal, interest and escrow parts.
The 28/36 math, step by step
The tool runs five steps: split income into months, apply both caps, take the smaller, convert it to a loan with the annuity factor, then add the down payment.
Front-end cap = 28% × Monthly income
Back-end cap = 36% × Monthly income − Monthly debts
Max housing payment = the smaller of the two caps
Max loan = Max payment × [((1+r)n − 1) ÷ (r(1+r)n)], where r = APR ÷ 12 and n = years × 12 (at a 0% rate the factor is simply n)
Max home price = Max loan + Down payment
Two behaviours worth knowing before you trust the output. First, when debts leave the back-end cap at zero or below, the tool prints a does-not-qualify message instead of a negative loan: on $120,000 of income that wall sits at $3,600 a month of debts. Second, at an exact tie between the caps ($800 a month of debts on that income) floating-point arithmetic makes the back-end cap a hair smaller, so the tool labels the tie as back-end bound. The payment is $2,800 either way; only the label is a coin toss.
Worked example: $120,000 income, $500 of debts, 6.5% for 30 years
The pre-filled run is the standard case: $10,000 a month gross, a $2,800 front-end cap against a $3,100 back-end cap, and a 158.21 annuity factor turning the payment into a $442,990.29 loan. Here is the same household at other debt levels, every cell a verified run of the tool above.
| Monthly debts | Max payment | Binding cap | Max loan | Max price |
|---|---|---|---|---|
| $0 | $2,800.00 | Front-end 28% | $442,990.29 | $482,990.29 |
| $500 (worked example) | $2,800.00 | Front-end 28% | $442,990.29 | $482,990.29 |
| $1,000 | $2,600.00 | Back-end 36% | $411,348.13 | $451,348.13 |
| $1,500 | $2,100.00 | Back-end 36% | $332,242.72 | $372,242.72 |
| $2,000 | $1,600.00 | Back-end 36% | $253,137.31 | $293,137.31 |
| $3,000 | $600.00 | Back-end 36% | $94,926.49 | $134,926.49 |
| $3,600 | $0 | Back-end 36% | Does not qualify at these ratios | |
Read the max price column as bars and the shape of the rule is clear: flat while the front-end cap binds, then a straight staircase down once debts pass $800.
What each income supports at 6.5%
At the worked example’s debts, down payment, rate and term, price scales with income, but not evenly: at $60,000 the $500 of debts already pushes the household onto the back-end cap, while every income from $80,000 up is front-end bound.
| Annual income | Max payment | Binding cap | Max price |
|---|---|---|---|
| $60,000 | $1,300.00 | Back-end 36% | $245,674.07 |
| $80,000 | $1,866.67 | Front-end 28% | $335,326.86 |
| $100,000 | $2,333.33 | Front-end 28% | $409,158.58 |
| $120,000 | $2,800.00 | Front-end 28% | $482,990.29 |
| $150,000 | $3,500.00 | Front-end 28% | $593,737.87 |
| $200,000 | $4,666.67 | Front-end 28% | $778,317.16 |
Rates move the same payment just as hard. Holding the worked example fixed, a 5.5% rate supports a $533,140.94 price, 6.5% supports $482,990.29, and 7.5% supports $440,449.36: a two-point rate swing is worth about $92,691.58 of house. The Federal Reserve’s consumer mortgage guidance makes the same practical point from the lender’s side: the rate you are offered depends on your credit and the loan’s features, which is why shopping more than one lender matters as much as the ratio math.
How 28/36 compares with the ratios lenders actually use
The 28/36 pair is a guideline with a long history, not a current regulatory cap, and this page keeps it because it is the conservative benchmark a buyer can sanity-check a pre-approval against. Program rules today are looser and program-specific.
| Program | Housing (front-end) | Total debts (back-end) | Notes |
|---|---|---|---|
| This calculator (28/36 guideline) | 28% | 36% | Principal and interest only; the comfort benchmark |
| Conventional, manually underwritten (Fannie Mae) | No separate cap in the guide | 36%, up to 45% with qualifying credit and reserves | Selling Guide B3-6-02 |
| Conventional, Desktop Underwriter (Fannie Mae) | No separate cap in the guide | Up to 50% on strong files | Automated risk assessment decides case by case |
| FHA (HUD Handbook 4000.1) | 31% | 43%, higher with compensating factors | Manual ratios; automated approvals can run higher |
| VA | No front-end ratio | 41% guideline | Residual income is the primary test; over 41% needs closer scrutiny |
| USDA Guaranteed | 29% | 41% | Ratio waivers can reach 32/44 with strong factors |
The CFPB’s general Qualified Mortgage definition no longer carries a fixed 43% DTI limit either: since the 2021 revision it rests on price-based thresholds, per the Bureau’s Ability-to-Repay and Qualified Mortgage Rule compliance guide. The practical reading: if this calculator says you qualify at 28/36, you are comfortably inside every mainstream program’s ratios. If it says you do not, a government-backed program may still take you, which is a question for the home loan approval calculator and then a lender, not a reason to stretch a household budget to a number a website printed.
The honest gap: this tool prices principal and interest only
A lender’s housing ratio covers PITI, not P&I alone, and the difference is large enough to change the answer. On the worked example’s $482,990.29 home, property tax at 1.1% of value runs about $443 a month and insurance about $200 a month: roughly $643 of the $2,800 cap is spoken for before principal and interest, which would pull the supportable loan down by about $101,700 at the same factor.
That illustration uses round tax and insurance assumptions, not tool outputs, and it is the single biggest reason to treat this page as a qualifying screen rather than a shopping budget. Add HOA dues and, under 20% down, private mortgage insurance, and the gap widens again. Freddie Mac’s fixed-rate product guidance caps manually underwritten total ratios at 45% on the full housing expense, which shows how much definition matters: the same borrower is at 28% on this page’s P&I definition and well above it on a PITI definition.
Five moves that raise your qualifying price
The fastest gains come from the back-end side, because debts subtract from the cap dollar for dollar once they pass the 8-point gap.
- Kill the debt with the biggest payment, not the biggest balance. Ratios count payments. Clearing a $400 car payment frees $400 of housing room; the same cash against a card balance whose minimum barely moves frees almost none.
- Check the 10-month line. Under the CFPB’s Appendix Q approach, obligations with under ten months left may be treated differently when they do not affect your ability to pay right after closing. Ask the lender before you spend cash clearing a nearly finished loan.
- Do not open new credit before you apply. A new car lease or furniture loan lands directly in the back-end numerator, and the HUD housing counselor training materials walk through exactly this trap for first-time buyers.
- Raise documented income where you honestly can. A co-borrower with income and little debt lifts both caps; a co-borrower with heavy debts can lower the result, because their debts join the numerator too.
- Price the term honestly. A 15-year term qualifies you for less house on purpose: the payment per dollar is higher. If the goal is the largest approval, 30 years wins; if the goal is the least interest, run both and compare, and see what extra principal does later with the loan additional payment calculator.
What competing calculators miss
Most affordability tools are richer than this one on inputs and weaker on the one thing that decides the answer: which cap binds, and what the caps leave out.
- Bankrate’s home affordability calculator: the deepest rival, with location, credit tiers and full PITI. Its recommended-versus-maximum framing is genuinely good. It still presents one budget number without naming the binding ratio, so a debt-heavy reader cannot tell whether to fix debts or income.
- NerdWallet’s how-much-house tool: strong guidance and a credit-score input, but the result is a single affordability figure with the ratio logic buried in the surrounding article.
- MLCALC’s affordability calculator: unusually transparent, with PITI, PMI and HOA broken out and a binding-constraint sentence. It is the closest rival on honesty; it does not show the debt ladder, so the reader never sees that the first slice of debt is free under the caps.
- DevZone and the preset-driven tools: DTI presets (28/36, 30/40, 33/43) are a nice touch this page deliberately skips, because a preset quietly changes the rule being tested. This page tests one named rule and shows its work.
- The gap this page fills: both caps applied and named, a does-not-qualify guard instead of a negative loan, the debt ladder and income tables run through the actual tool, and an open statement of the two places the guideline has aged: modern programs approve well past 36%, and real ratios run on PITI while this tool runs on principal and interest.
Frequently asked questions
The 28/36 rule is a long-standing qualifying guideline: housing costs at or under 28% of gross monthly income (the front-end ratio), and housing plus all other monthly debts at or under 36% (the back-end ratio). This calculator applies both caps, uses whichever is lower, and converts that payment into a maximum loan and home price. It is a guideline, not a law: Fannie Mae manual underwriting uses a 36% total ratio, its automated system can approve up to 50%, and FHA, VA and USDA each run their own ratios.
At 6.5% over 30 years with $500 a month of other debts and $40,000 down, this calculator gives a maximum housing payment of $2,800, a maximum loan of $442,990.29 and a maximum home price of $482,990.29. The front-end 28% cap binds in that example. Change the debts to $2,000 a month and the back-end cap binds instead, cutting the maximum price to $293,137.31.
Recurring obligations: minimum payments on credit cards, car loans and leases, student loans, personal loans, child support, alimony and other debts that run ten months or more. Groceries, utilities, phone bills, subscriptions and insurance premiums you pay yourself do not count. Lenders count payments, not balances, so a small loan you can clear completely frees up more qualifying room than the same cash spread across a large loan.
No. The 36% back-end cap in this tool matches Fannie Mae’s manually underwritten maximum, but Fannie Mae’s Desktop Underwriter can approve total ratios up to 50% for strong files, FHA’s standard ratios are 31% front and 43% back with higher approvals possible, VA uses 41% as a guideline alongside residual income, and USDA uses 29% and 41%. Treat the 28/36 result as a conservative qualifying estimate, and expect a lender working in a different program to quote a different ceiling.
No. It sizes principal and interest only, even though a lender’s housing ratio normally covers the full PITI payment: principal, interest, property taxes, homeowners insurance, mortgage insurance and HOA dues where they apply. Your real qualifying payment will be lower than the figure shown once those costs are added, so budget them on top before you shop.
The term sets the annuity factor that converts a monthly payment into a loan amount. At 6.5%, the $2,800 payment in the worked example supports $442,990.29 over 30 years, $375,550.01 over 20 years and $321,429.95 over 15 years. A shorter term means a higher payment per dollar borrowed, so the same income qualifies for a smaller loan, but you pay far less interest and own the home sooner.
The calculator returns a does-not-qualify message instead of a loan amount, because the back-end cap leaves no room for any housing payment. That is a statement about these two ratios, not about every loan program: some programs approve higher ratios. Inside the 28/36 frame, paying down the debt with the largest monthly payment buys back qualifying room fastest.
It depends where you sit. On a $120,000 income the first $800 a month of debts costs nothing under these caps, because the 28% front-end cap binds first. Past that point every extra $500 a month of debt removes $500 of housing payment, which at 6.5% over 30 years is $79,105.41 of loan amount. The popular claim that $500 of debt always costs about $100,000 of home price overstates it at this rate and ignores the free first $800.
No. This is the guideline math only, run on the income, debts, down payment, rate and term you enter. A real pre-approval also weighs your credit history, employment and income documentation, cash reserves, the property appraisal and the rules of the specific loan program you apply under.
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References
- Consumer Financial Protection Bureau. Appendix Q to Part 1026: Standards for Determining Monthly Debt and Income. Accessed October 22, 2026.
- Fannie Mae. Selling Guide B3-6-02: Debt-to-Income Ratios. Accessed October 22, 2026.
- Fannie Mae, Your Home. Why Understanding Debt Is Essential. Accessed October 22, 2026.
- Freddie Mac Single-Family. Fixed-Rate Mortgages: Product Features and Maximum Debt-to-Income Ratio. Accessed October 22, 2026.
- U.S. Department of Housing and Urban Development. Single Family Housing Policy Handbook 4000.1: Borrower Qualifying Ratios. Accessed October 22, 2026.
- U.S. Department of Veterans Affairs. 38 CFR 36.4340: Underwriting Standards, Debt-to-Income Ratio and Residual Income. Accessed October 22, 2026.
- Congressional Research Service. USDA Rural Housing Programs: An Overview (29/41 Guaranteed Loan Ratios). Accessed October 22, 2026.
- U.S. Department of Housing and Urban Development, Housing Counselors Training. Module 2.1 Study Guide: Front-End and Back-End Ratios. Accessed October 22, 2026.
- Consumer Financial Protection Bureau. Regulation Z, Section 1026.43: Minimum Standards for Transactions Secured by a Dwelling (Ability-to-Repay and Qualified Mortgage Rule). Accessed October 22, 2026.
- Consumer Financial Protection Bureau. Mortgages: Consumer Tools and Resources. Accessed October 22, 2026.