Your payment is four things, not one
Lenders and property listings quote “the mortgage,” but the money that leaves your account each month is usually four separate costs bundled together. The industry shorthand is PITI:
A $350,000 home, $70,000 down, 6.5% over 30 years
- Principal & interest
- $1,769.79
- Property tax ($3,600/yr)
- $300.00
- Home insurance ($1,200/yr)
- $100.00
Total monthly payment = $2,169.79
The loan itself accounts for about 82% of that figure. Budget only for principal and interest and you will be short by roughly $400 every month — which is precisely the gap that catches first-time buyers. Lenders normally collect tax and insurance into an escrow account alongside the loan payment, so the bundled figure is what you actually plan around.
Why the early years feel like standing still
Interest is charged on what you still owe, and at the start you owe nearly everything. On the loan above, the first payment splits roughly $1,517 to interest and just $253 to principal. After a full year of payments totalling over $21,000, the balance has dropped by only about $3,100.
That ratio inverts slowly. On this loan it takes until year 19 before principal finally makes up the larger half of a payment. It also explains why overpaying early is so effective: money put in during year one erases principal that would otherwise have accrued interest for another 29 years, while the same sum in year 28 saves almost nothing.
Which lever to pull
Three inputs control the payment, and they do not work equally. A bigger down payment reduces the loan proportionally — the most direct lever, if you have the cash. A lower rate reduces the interest without touching the debt, which is why shopping lenders is worth real effort. A longer term reduces the monthly figure but raises lifetime cost sharply, so treat it as an affordability tool rather than a saving.
This calculator covers principal, interest, tax, and insurance. Depending on your loan and location you may also owe private mortgage insurance (common below a 20% down payment) or HOA fees, neither of which is included here. Your lender’s formal quote is the binding figure.