How this is calculated
monthly = loan × r ÷ (1 − (1 + r)^−n), where loan = price × (1 − down %), r = rate ÷ 12, n = months
The payment uses the standard amortization formula on the financed amount (price minus down payment). It covers principal and interest only — the number a real US escrow payment adds on top includes property taxes, homeowner's insurance and possibly PMI and HOA fees, which together commonly add 25-50% to the monthly figure shown.
The lifetime interest number deserves a long look. A $280,000 loan at 6.5% for 30 years costs roughly $357,000 in interest — the house effectively costs double its sticker. The balance chart explains why: for the first decade, most of each payment services interest, and equity builds slowly. This is also why a 15-year mortgage, despite the larger payment, costs radically less in total.
Rates move the picture more than prices at these scales: one percentage point on a $280,000 loan changes the payment by roughly $180 a month and the lifetime cost by ~$65,000. It's why buyers rate-shop mortgages harder than they price-negotiate houses — or should.
Frequently asked questions
What else joins the monthly payment in real life?
Property taxes (commonly 1-2% of home value yearly), homeowner's insurance, PMI if the down payment is under 20%, and HOA fees where applicable. Budget with those included — lenders do.
15-year or 30-year?
The 15-year saves enormous interest and builds equity fast but demands a bigger payment; the 30-year's flexibility is real (you can always pay extra to simulate a 15). Many pick the 30 and overpay — the discipline is the hard part.
How much house can I afford?
The classic guideline caps housing costs at 28% of gross monthly income. Our home affordability calculator runs that math from the income side.