The whole monthly payment, not just the loan

What this calculator includes that most leave out

A mortgage quote is principal and interest — the check that goes to the lender. What leaves your account each month is PITI and then some: property taxes and the insurance premium (usually escrowed into the same payment), HOA dues where they apply, and the utilities a landlord ends up carrying. This calculator asks for all of it and totals all of it, because deciding whether a payment is affordable on the P&I number alone is how a comfortable payment turns out not to be.

How the payment is computed

A fixed-rate mortgage charges interest monthly on whatever balance remains, and the level payment is set so the loan lands on exactly zero at the last month: payment = P·r(1+r)ⁿ ⁄ ((1+r)ⁿ−1), with P the loan amount, r the monthly rate and n the number of payments. Early on the balance is large, so most of the payment is interest; each month the balance falls slightly and the split shifts. The year-by-year table above shows the shift directly — the principal-share bar starts thin and widens every year.

What moves the number

The rate matters more than people expect and the term matters differently than people expect. A point of rate on a $400,000 loan moves the payment by roughly $250 a month, and moves the lifetime interest by tens of thousands. A shorter term raises the payment but collapses the interest: the same loan over 15 years instead of 30 roughly doubles the speed at which the balance falls while cutting total interest by more than half. Try both in the fields above — the schedule recomputes as you type, so the comparison costs nothing.

Reading the amortization schedule

Each year row totals that year's payments, splits them into principal and interest, and shows the balance still owed at year end. Open a year to see its twelve payments. Two things worth noticing: the month where principal overtakes interest for the first time — on a 30-year loan at recent rates it arrives shockingly late — and the way the final years are almost all principal, which is why the last stretch of a mortgage retires the balance so quickly.

If the property is one of several you own, the number a lender will ask about next is how the whole portfolio carries itself — the free Schedule of Real Estate Owned generator builds that document the same way this page builds the payment.