Home Affordability Calculator
Work out how much house you can afford, using the DTI (debt-to-income) method behind the classic 28/36 rule. Enter your income, existing debts, expected rate and term — nothing is stored, and the result is an estimate, not a mortgage approval.
DTI is the share of gross income going to all debt, including the mortgage. The 28/36 rule caps it at 36%; qualified mortgages allow up to 43%. Leave the default unless you know your lender's limit.
This is an illustrative estimate only. Actual affordability and approval are determined by the lender based on your credit score and history, income verification, down payment and reserves, the property's appraised value, and underwriting — the figure shown is not a loan offer or pre-approval.
- New Housing Payment $2,160 (36.0%)
- Existing Debts $0 (0.0%)
- Remaining Income $3,840 (64.0%)
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How Much House Can I Afford? (DTI)
Lenders cap your total debt at a share of income called DTI. Max Payment = (Gross Income × DTI%) − Existing Debts, and the loan that payment can service is its present value over your term at the expected rate. Example: $6,000 income, no existing debts, 36% DTI, 7% over 30 years gives a $2,160 affordable payment and an estimated affordable loan of about $324,664. This is an estimate only, not a mortgage approval.
Estimated Affordability by Term
Your affordable payment is set by your income, so it stays the same across terms — but a longer term lets that payment service a larger loan, at the cost of much more total interest.
| Term | Max Affordable Payment | Estimated Affordable Loan | Indicative Total Interest |
|---|---|---|---|
| 15 Years | $2,160 | $240,313 | $148,487 |
| 20 Years | $2,160 | $278,602 | $239,798 |
| 25 Years | $2,160 | $305,612 | $342,388 |
| 30 Years (your term) | $2,160 | $324,664 | $452,936 |
Estimate only, not a loan offer or pre-approval. Your affordable payment must also cover property tax, homeowners insurance, and PMI if your down payment is under 20% — so a realistic loan is somewhat lower than shown. Actual approval depends on your credit, income verification, down payment, the appraisal, and lender underwriting. No personal data is collected — the figures you enter are used only in your browser and never stored.
How a Home Affordability Calculator Works
"How much house can I afford?" is really two questions in one. There is the price of the home you want, and there is the mortgage payment your income can comfortably carry every month. A lender starts from the second question, works it backwards into a loan amount, and that is what an affordability calculator estimates — using the same debt-to-income logic mortgage underwriters apply.
DTI and the 28/36 rule
The central idea is your debt-to-income ratio (DTI) — the share of your gross monthly income that goes toward debt payments. The long-standing benchmark is the 28/36 rule: no more than 28% of gross income on housing costs (the front-end ratio), and no more than 36% on all debt combined, including the new mortgage (the back-end ratio). The back-end ratio is the binding limit, because it counts your other obligations too, so that is what this calculator uses.
The affordable housing payment starts from your income and the DTI cap, then subtracts what you already owe each month:
Max Affordable Payment = (Gross Monthly Income × DTI%) − Existing Debts
If you earn $6,000 a month, the lender allows a 36% back-end DTI, and you have no other debt, then $2,160 a month is available for housing. If you already pay $900 toward a car and student loan, only $1,260 remains — which is why existing debt reduces how much home you can afford so directly.
From affordable payment to loan amount
Once the affordable payment is known, the calculator runs a mortgage calculation in reverse. Instead of asking "what payment does this loan require?", it asks "what loan can this payment support?" over your chosen term at the expected rate. Mathematically it is the present value of your payment treated as a stream of monthly instalments:
Max Loan = Payment × [ (1 + r)n − 1 ] / [ r × (1 + r)n ], where r is the monthly interest rate and n is the number of months.
A $2,160 payment over 30 years at 7% supports a loan of roughly $325,000. Change any input — income, existing debt, rate or term — and the figure moves, which is exactly what the calculator lets you explore instantly.
Why the term changes your affordability
Because affordability is anchored to the payment your income supports, a longer term spreads that payment over more months and therefore services a larger loan. The affordability-by-term table above makes it concrete: the payment stays at $2,160 whether you pick 15 years or 30, but the estimated affordable loan climbs from around $240,000 to about $325,000. The catch is the total interest, which rises steeply with the term — affording more by stretching the loan means paying far more for the money over its life, and longer terms often carry a slightly higher rate too.
What the payment really has to cover
Here is the honest caveat. This calculator converts your entire affordable housing payment into loan principal and interest, but a real monthly housing payment — often called PITI — has to cover more than that: principal, interest, property taxes, and homeowners insurance, plus private mortgage insurance (PMI) if your down payment is under 20%, and any homeowners-association dues. Those items can easily take several hundred dollars a month, and every dollar they consume is a dollar not available for principal and interest. So the loan a lender actually approves is usually somewhat lower than a pure payment-to-loan conversion suggests. Treat the estimate here as an upper bound, and leave a cushion for taxes and insurance when you set your real budget.
What lenders also weigh
A ratio-based estimate uses only the numbers you type in, but a lender's decision rests on much more. Your credit score affects both whether you are approved and the rate you are offered, which in turn changes how much a given payment can borrow. Your down payment and cash reserves matter — a larger down payment shrinks the loan and can remove PMI, while reserves reassure the lender you can weather a rough patch. Employment and income stability, the property's appraised value, and the loan program all feed into underwriting. None of these can be captured by an income ratio, which is why the number here is a planning estimate, not a promise to lend.
Ways to afford more home
If the estimate falls short, several levers genuinely help. Paying down existing debt — especially a car loan or credit-card balance — frees up your DTI allowance immediately, often the fastest win. Improving your credit score before you apply can earn a lower rate, and a lower rate lets the same payment buy a larger loan. Saving a bigger down payment reduces the loan you need and can eliminate PMI, freeing room in the payment. Adding a co-borrower with steady income raises the income the ratio is applied to. And shopping several lenders for a better rate can meaningfully change what you qualify for. Each of these is a real, sound way to strengthen your position — unlike simply stretching to the top of a 43% DTI, which lenders may allow but which can leave you uncomfortably tight month to month.
A note on DTI limits
The 36% back-end ratio is a guideline, not a hard wall. Conforming qualified mortgages generally permit a back-end DTI up to 43%, and some programs go higher when strong compensating factors — a high credit score, a large down payment, or substantial reserves — are present. A higher DTI increases the loan you may qualify for, but it also means a larger slice of every paycheck is committed before you have spent anything on living, saving, or emergencies. The advanced DTI field lets you model the range; the 36% default is a sensible, comfortable middle ground. Use the estimate to set a realistic price range and shortlist homes, then get a formal pre-approval from the lenders you actually intend to use before you make an offer.
Affordability Calculator — Frequently Asked Questions
DTI is your debt-to-income ratio — the share of your gross monthly income that goes to debt payments. The 28/36 rule is a common lender guideline: no more than 28% of gross income on housing costs (the front-end ratio) and no more than 36% on all debt combined including the mortgage (the back-end ratio). This calculator works from the back-end DTI cap, since that is the ceiling that limits how large a payment your income can support once existing debts are counted.
The back-end DTI includes your future mortgage payment plus recurring debts a lender sees on your credit report — car loans, student loans, personal loans, and minimum credit-card payments. It does not usually include your current rent (which the mortgage replaces) or everyday costs like utilities, groceries or insurance that are not debt. Enter your existing monthly debt payments so the calculator subtracts them from your allowance first.
No. This tool gives an illustrative estimate from the income, debts, rate and term you enter. A real pre-approval or approval depends on your credit score and history, employment and income verification, down payment and cash reserves, the property's appraised value, and the lender's own underwriting. The figure here is not a loan offer, pre-approval, or commitment to lend — use it to set a realistic budget, then get pre-approved by a lender.
While 36% is the classic benchmark, many lenders go higher. A conforming qualified mortgage generally allows a back-end DTI up to 43%, and some loan programs stretch further with compensating factors like a strong credit score, a large down payment, or significant cash reserves. A higher DTI increases the loan you may qualify for but also raises your risk of being stretched thin, so treat the upper end with caution. The advanced DTI field lets you model 28% to 43%.
Yes. Because affordability is driven by the monthly payment your income supports, a longer term spreads that payment over more months and lets it service a larger loan — the affordability-by-term table shows how much. A 30-year term supports a bigger mortgage than a 15-year one for the same payment. The trade-off is far more total interest over the life of the loan, and often a slightly higher interest rate on longer terms.
Not directly. The calculator converts your whole affordable housing payment into loan principal and interest. In reality that payment also has to cover property tax, homeowners insurance, and — if your down payment is under 20% — private mortgage insurance (PMI), plus any HOA dues. Those costs reduce how much of the payment is left for principal and interest, so a realistic loan figure is somewhat lower than the estimate. Treat the result as an upper-bound starting point and leave room for taxes and insurance.