How Much Mortgage Does Your Monthly Payment Buy?
House hunting usually starts from the other end of the math: not "what does this house cost per month" but "I can spend $2,000 a month — what mortgage does that get me?" The translation is mechanical once you fix a rate and a term, and it's worth knowing before you fall for a listing.
The Quick Answer
At mid-2026 average rates — roughly 6.5% on a 30-year fixed and 5.8% on a 15-year — each dollar of monthly principal-and-interest supports about $158 of 30-year loan, or about $120 of 15-year loan:
| Monthly P&I | 30-year loan (~6.5%) | 15-year loan (~5.8%) |
|---|---|---|
| $1,500 | ≈ $237,000 | ≈ $180,000 |
| $2,000 | ≈ $316,000 | ≈ $240,000 |
| $2,500 | ≈ $396,000 | ≈ $300,000 |
| $3,000 | ≈ $475,000 | ≈ $360,000 |
| $3,500 | ≈ $554,000 | ≈ $420,000 |
| $4,000 | ≈ $633,000 | ≈ $480,000 |
Add your down payment on top of the loan amount to get the price range you can shop in. Rates move weekly, so treat the table as a map, not a quote — the affordability calculator runs the same math with current inputs.
The Formula Behind the Table
The loan amount is the monthly payment times an annuity factor that depends only on the rate and term:
Loan = payment × (1 − (1 + i)⁻ⁿ) ÷ i
where i is the monthly rate (annual rate ÷ 12) and n the number of payments. At 6.5% over 360 months the factor works out to about 158. That single number explains most of what you feel when rates move: at 5%, a dollar of payment bought about $186 of loan; at 7%, about $150. A one-point rate change swings your buying power by roughly 10% without your budget changing at all.
The Payment Is More Than the Loan
The table covers principal and interest only. The check you actually write each month — lenders call it PITI — also includes:
- Property taxes — commonly 1% to 2% of the home's value per year, collected monthly.
- Homeowners insurance — a few thousand dollars a year in much of the country, more in coastal and disaster-prone states.
- PMI — if you put down less than 20% on a conventional loan.
- HOA dues — on condos and many newer developments.
Together these routinely eat 20-30% of the total payment. If $2,500 a month is your ceiling, budget something like $1,900-$2,100 for P&I and check the rest against the actual tax and insurance figures for the homes you're looking at.
What Lenders Will Let You Do
Your budget and the lender's ceiling are different numbers. Underwriting works from your debt-to-income ratio: the classic guideline caps housing costs at 28% of gross monthly income and all debt payments at 36%, and many loans stretch further. A $2,500 housing budget is comfortable on a $9,000 gross monthly income and a stretch on $6,000 — even if your spreadsheet says otherwise, the lender's cap is the one that binds. Getting pre-approved early tells you which number you're actually shopping with.
Stretching the Same Budget
If the table says less house than you hoped, the levers are the same ones that set the factor:
- Shop the rate. Quotes on the same day routinely differ by a quarter point between lenders — that's roughly 2-3% of buying power for an afternoon of calls.
- Consider discount points if you'll keep the loan long enough to break even.
- Put more down. Every extra dollar of down payment is a dollar of price that needs no financing — and reaching 20% drops PMI from the payment.
- Improve the credit tier. Rates are priced in credit-score bands, so crossing a threshold repriced the whole loan.
Then run your own numbers in the affordability calculator — it starts from your income and debts rather than a round payment, which is how the lender will look at you.
