How much can I borrow for a mortgage?

Lenders size your loan from your debt-to-income limits. Your housing payment is capped near 28 percent of gross monthly income (the front-end ratio) and your total debt near 36 percent (the back-end ratio), with many loans allowing up to about 43 percent. This calculator takes the lower cap, subtracts estimated taxes and insurance to find the principal and interest you can afford, then works backward through the mortgage payment formula to the loan amount that payment supports.

How do lenders decide how much I can borrow?

The main lever is your debt-to-income ratio. A lender sets a maximum housing payment from your income and DTI limits, then checks that your total debt stays under the back-end limit. Your credit score, cash reserves, employment history, and the loan program adjust the limits up or down, and the interest rate you are offered determines how large a loan a given payment can carry. Two people with the same income can qualify for very different amounts based on their existing debts and credit.

What DTI do I need to qualify for a mortgage?

The conventional comfort zone is the 28/36 rule: housing at or below 28 percent of gross monthly income and total debt at or below 36 percent. Many programs allow a back-end ratio up to about 43 percent, the qualified-mortgage reference point, and some go higher with strong credit or reserves. A lower DTI generally means easier approval and a larger loan for the same income, because more of your income is free for the payment.

Is this a pre-approval?

No. This is a qualification estimate built from your income, debts, and DTI limits, not a lender decision. A real pre-approval verifies your income and assets and weighs your credit score, reserves, employment, and the specific loan program, and it locks in a rate that changes these numbers. Use this to gauge your approximate borrowing power, then confirm the actual figure with a lender.

What does my result mean?

The max loan amount is what your income and debts support at these DTI limits. The binding limit tells you what is holding you back: if the front-end ratio binds, your income sets the ceiling and paying down debt will not raise it; if the back-end ratio binds, your other debts are the limit, so reducing them raises how much you can borrow. The max home price adds your down payment to the loan.

How Much Can I Borrow Calculator

Estimate the maximum mortgage you qualify for from your income, debts, and DTI limits, with the binding limit and the maximum home price it supports.

Gross monthly income

Other monthly debt payments

Interest rate

Loan term

years

Property tax

Homeowners insurance

Monthly HOA dues

Down payment

Front-end DTI limit

Back-end DTI limit

X f in

Max loan amount

$261,047.85

Max monthly housing payment: $2,100.00
Max principal and interest: $1,650.00
Max home price (with down payment): $331,047.85
Binding limit: Front-end (28% rule)
What this means: You qualify to borrow up to the amount shown, subject to a lender's full review

Which limit binds

DTI limit	Monthly housing payment
Front-end (28% of income)	$2,100.00
Back-end (36% of income minus debts)	$2,200.00
Binding max housing payment	$2,100.00

Quick answer: With the example inputs this page loads by default, the headline result (Max loan amount) comes to $261,047.85. Estimate the maximum mortgage you qualify for from your income, debts, and DTI limits, with the binding limit and the maximum home price it supports. Change any input above and every figure updates instantly in your browser.

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Fact-check: results on this page are verified against an independently coded reference oracle that covers all 106 calculators on this site. See how we verify .

How much you can borrow is set by your debt-to-income limits, not just your income. Lenders cap your housing payment near 28 percent of gross monthly income (the front-end ratio) and your total debt near 36 percent (the back-end ratio, up to about 43 percent for many loans). This calculator takes the lower cap, subtracts taxes and insurance to find the principal and interest you can afford, then works back to the maximum loan amount.

What this result means

The headline is the maximum loan your income and debts support at these DTI limits. The binding constraint tells you which rule is holding you back: when the front-end ratio binds, your income alone sets the ceiling and paying down debt will not raise it; when the back-end ratio binds, your other monthly debts are the limit, so reducing them directly increases how much you can borrow. Raising the back-end limit toward the 43 percent qualified-mortgage line lifts the maximum but leaves a tighter budget after the payment. Remember this is a qualification estimate built from ratios, not a pre-approval: a lender also weighs your credit score, cash reserves, employment history, and the specific loan program, and the rate you are actually offered will move these numbers. Treat the result as your approximate borrowing power and confirm the real figure with a lender. This is an estimate for education, not financial advice or a loan commitment.

Assumptions

This calculator inverts the debt-to-income (DTI) ratio: instead of starting from a home price, it starts from your income and debts and solves for the loan you qualify for. It uses the standard 28/36 rule, and both percentages are adjustable inputs (many programs allow a back-end ratio up to about 43 percent, the qualified-mortgage ceiling).
The front-end cap is gross monthly income times the front-end limit (28 percent by default). The back-end cap is gross monthly income times the back-end limit (36 percent by default) minus your other monthly debt payments (car loans, student loans, and credit card minimums, not rent). The binding max housing payment is the lower of the two caps, and the calculator reports which one binds; it is floored at zero, so debts above the back-end budget give no capacity rather than a negative payment.
The housing payment is full PITI (principal, interest, taxes, and insurance, plus HOA), consistent with how DTI is measured. To isolate the principal and interest, the calculator subtracts your estimated monthly taxes, insurance, and HOA from the binding housing payment. Property tax and insurance are entered as annual amounts and divided by 12; HOA is monthly. Because no home price is known yet, these are fixed dollar estimates rather than a percent of price, which is the main difference from the home affordability calculator.
The max principal-and-interest payment is floored at zero: if your estimated taxes, insurance, and HOA use up the entire housing payment, there is no room for a loan.
The max loan is found by inverting the standard mortgage payment formula: loan equals the max principal-and-interest payment divided by the monthly payment factor for your rate and term (the same shared factor the mortgage and affordability calculators use, so the payment math is never duplicated). Feeding the max loan back through the forward payment reproduces the max principal and interest, within a rounding cent.
The max home price is a secondary figure: the max loan plus the down payment you enter. The down payment does not affect the loan you qualify for here; it only converts that loan into a price. PMI, which a low down payment would add, is not modeled in the housing payment.
All figures are in nominal dollars, the interest rate is fixed for the full term, and each amount is rounded to the nearest cent.
DTI limits are lender guidelines, not guarantees. This is a qualification estimate, not a pre-approval: a lender also weighs your credit score, cash reserves, employment history, and the loan program, and your actual rate will change these figures. This is an estimate for educational purposes only, not financial, legal, or tax advice. Consult a lender for figures specific to your situation.

Key terms

Definitions for the terms this calculator uses, in our finance glossary .

How much you can borrow, and how it is calculated

This calculator answers the borrowing-power question: given your income, your existing debts, and the debt-to-income limits a lender uses, what is the largest mortgage you qualify for? It is the inverse of the debt-to-income (DTI) ratio. Where the home affordability calculator starts from a price and works to a payment, this one starts from your income and works to a loan.

Two DTI caps set the housing payment

Lenders apply the 28/36 rule. Two ceilings limit your monthly housing payment:

front-end cap = gross monthly income x front-end limit

back-end cap = gross monthly income x back-end limit - other monthly debts

The front-end limit defaults to 28 percent and the back-end to 36 percent (many loan programs allow the back-end ratio up to about 43 percent, the qualified-mortgage ceiling, which you can set). The binding max housing payment is the lower of the two caps:

max housing payment = max(0, min(front-end cap, back-end cap))

It is floored at zero, so when your existing debts already exceed the back-end budget there is simply no room for a payment, never a negative one. The calculator reports which cap binds, because that tells you what is holding you back: the front-end cap depends only on income, while the back-end cap falls as your other debts rise.

Isolate principal and interest

The housing payment is full PITI (principal, interest, taxes, and insurance, plus HOA), the same definition DTI uses. To find how much is left for the loan itself, subtract the fixed monthly escrow:

max P&I = max(0, max housing payment - monthly taxes - monthly insurance - monthly HOA)

Property tax and insurance are entered as annual amounts and divided by 12; HOA is monthly. Because no home price is known yet, these are fixed dollar estimates rather than a percent of a price, which is the main structural difference from the affordability calculator. If the escrow uses up the whole housing payment, the max P&I is zero and no loan is supported.

Invert the payment formula to a loan

The standard mortgage payment is payment = loan x paymentFactor, where the monthly payment factor is r(1+r)^n / ((1+r)^n - 1) with r the monthly rate and n the number of months (or 1/n at a zero rate). Solving for the loan simply divides:

max loan = max P&I / paymentFactor

This uses the same shared payment factor the mortgage and affordability calculators use, so the payment math is never duplicated and no exponentiation is written here. Feeding the max loan back through the forward payment reproduces the max P&I to within a rounding cent, which is the check that proves the inversion. Finally, the secondary max home price is the loan plus your down payment:

max home price = max loan + down payment

Worked example

Using the defaults: $7,500 gross monthly income, $500 in other monthly debts, a 6.5 percent rate over 30 years, $3,600 annual property tax, $1,800 annual insurance, no HOA, a $70,000 down payment, and the 28/36 limits.

front-end cap = $7,500 x 28% = $2,100
back-end cap = $7,500 x 36% - $500 = $2,200
binding max housing payment = min($2,100, $2,200) = $2,100 (the front-end ratio binds)
monthly escrow = $3,600 / 12 + $1,800 / 12 = $300 + $150 = $450
max P&I = $2,100 - $450 = $1,650
payment factor at 6.5% over 30 years is about 0.0063207
max loan = $1,650 / 0.0063207 = $261,047.85
max home price = $261,047.85 + $70,000 = $331,047.85

So on this income, with these debts and escrow, the borrower qualifies for about a $261,000 loan and, with $70,000 down, a home price near $331,000. If the other debts were higher (say $1,200), the back-end cap would drop to $1,500 and become the binding limit, cutting the max loan to about $166,000: proof that paying down debt raises borrowing power only when the back-end ratio is what binds.

What this includes and excludes

It includes the two DTI caps, the binding logic, the escrow netting to isolate P&I, and the amortization inversion to a loan and price. It excludes PMI (a low down payment would add it to the housing payment), your credit score, cash reserves, employment history, and loan-program-specific rules, all of which a lender weighs. It also excludes closing costs and the cash needed at closing. This is a qualification estimate, not a pre-approval, and lenders vary. This is an estimate for education, not financial, legal, or tax advice.

Sources

Consumer Financial Protection Bureau, guidance on debt-to-income ratio and how much you can borrow, at consumerfinance.gov (the 43 percent qualified-mortgage reference and the role of DTI in qualification).
Fannie Mae and Freddie Mac eligibility guidelines, on conventional DTI limits and the factors beyond DTI that lenders consider.

Frequently asked questions

How much can I borrow for a mortgage?: Lenders size your loan from your debt-to-income limits. Your housing payment is capped near 28 percent of gross monthly income (the front-end ratio) and your total debt near 36 percent (the back-end ratio), with many loans allowing up to about 43 percent. This calculator takes the lower cap, subtracts estimated taxes and insurance to find the principal and interest you can afford, then works backward through the mortgage payment formula to the loan amount that payment supports.
How do lenders decide how much I can borrow?: The main lever is your debt-to-income ratio. A lender sets a maximum housing payment from your income and DTI limits, then checks that your total debt stays under the back-end limit. Your credit score, cash reserves, employment history, and the loan program adjust the limits up or down, and the interest rate you are offered determines how large a loan a given payment can carry. Two people with the same income can qualify for very different amounts based on their existing debts and credit.
What DTI do I need to qualify for a mortgage?: The conventional comfort zone is the 28/36 rule: housing at or below 28 percent of gross monthly income and total debt at or below 36 percent. Many programs allow a back-end ratio up to about 43 percent, the qualified-mortgage reference point, and some go higher with strong credit or reserves. A lower DTI generally means easier approval and a larger loan for the same income, because more of your income is free for the payment.
Is this a pre-approval?: No. This is a qualification estimate built from your income, debts, and DTI limits, not a lender decision. A real pre-approval verifies your income and assets and weighs your credit score, reserves, employment, and the specific loan program, and it locks in a rate that changes these numbers. Use this to gauge your approximate borrowing power, then confirm the actual figure with a lender.
What does my result mean?: The max loan amount is what your income and debts support at these DTI limits. The binding limit tells you what is holding you back: if the front-end ratio binds, your income sets the ceiling and paying down debt will not raise it; if the back-end ratio binds, your other debts are the limit, so reducing them raises how much you can borrow. The max home price adds your down payment to the loan.

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By Sam Sage Last reviewed July 2026.