Monthly payment, lifetime interest, extra-payment payoff, and how much house your income supports.
Extra payments go straight to principal and shorten the loan.
PMI applies automatically when the down payment is under 20%, and drops off once you reach 20% equity.
Uses the 28/36 rule: housing under 28% of gross income, total debt under 36%.
This mortgage calculator breaks your monthly payment into principal, interest, taxes, insurance, PMI, and HOA (PITI), shows the lifetime interest on the loan, and reveals how much sooner extra payments retire the balance. It also runs an affordability check against the lender's standard debt-to-income guidelines.
The monthly principal-and-interest figure comes from the standard amortization formula: the loan amount times the monthly rate, divided by one minus (one plus the monthly rate) raised to the negative number of payments. On top of that we layer property tax, homeowners insurance, PMI when your down payment is under 20%, and any HOA dues to reach the full PITI payment. Extra payments are applied straight to principal each month, which is why even a small amount shortens the loan and cuts total interest so sharply.
The principal and interest portion comes from the standard amortization formula using your loan amount, rate, and term. We then add property taxes, homeowners insurance, PMI (if your down payment is under 20%), and any HOA dues to give the full PITI payment.
Most lenders use the 28/36 rule: housing should stay under 28% of gross monthly income and total debt under 36%. The affordability section works backward from your income and debts to a maximum price, and you can adjust the ratios.
Yes. Every extra dollar goes straight to principal, which shrinks the balance that future interest is charged on. Even small monthly extras can cut years off the loan and save tens of thousands in interest.
PITI stands for principal, interest, taxes, and insurance — the four parts of a typical mortgage payment. Lenders look at the full PITI (plus HOA and PMI) when deciding how much you can borrow, not just principal and interest.
Putting down 20% avoids PMI and lowers the loan, but many buyers put down less and pay PMI until they reach 20% equity. The calculator shows the payment and PMI cost at any down payment so you can weigh the trade-off.
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