Mortgage ToolkitHow mortgage payments work
Every mortgage payment is really several separate costs bundled into one number. This calculator adds up the five most common pieces: principal & interest (based on your home price, down payment, rate, and term), property tax and home insurance (entered as annual amounts and divided by 12), any HOA dues, and PMI — added automatically whenever your down payment is under 20% of the home price. Lenders often collect the tax and insurance portions into an escrow account and pay those bills on your behalf, but the total you owe each month is the same either way. Results above update instantly in your browser — nothing is stored on a server. Use copy share link to send this exact scenario to someone else, download a PDF report, or rely on automatic local saving in this browser.
Principal vs. interest
Principal is the portion of your payment that reduces what you owe on the loan. Interest is the cost of borrowing that money, charged on whatever balance remains. Early in a loan the balance is high, so most of each payment goes to interest; as the balance shrinks, more of each payment goes to principal — even though the total payment itself stays flat on a fixed-rate loan. The Payment Breakdown and Loan Balance tabs in the charts above show exactly how that mix shifts over your loan term, and the Interest Paid and Principal Paid tabs show the running totals. For a payment-by-payment view of that same shift, the mortgage amortization calculator builds out the full schedule.
Property taxes explained
Property tax is set by your local government (county, city, or school district) as a percentage of your home's assessed value, and it's billed annually or semi-annually even though most homeowners pay it monthly through escrow. Rates vary enormously by location — from under 0.5% of home value per year in some states to well over 2% in others — so the property tax field in this calculator is one of the most important to get right for your specific area rather than leaving it at the default. Your county assessor's website or a recent listing for a comparable home nearby are the most reliable sources for an accurate number.
Home insurance
Homeowners insurance protects the lender's collateral (and your own investment) against fire, storm damage, theft, and liability claims, and virtually every mortgage lender requires it as a condition of the loan. Premiums depend on your home's value, location, construction, and claims history, and — like property tax — are usually collected monthly through escrow and paid out annually by the lender. If you're in a flood zone or an area with elevated wildfire or hurricane risk, budget for a separate policy on top of standard homeowners coverage, since those perils are often excluded by default.
PMI explained
Private mortgage insurance protects the lender— not you — against default, and it's required automatically whenever your down payment is below 20% of the purchase price (a loan-to-value ratio above 80%). This calculator adds PMI to your monthly payment the moment your down payment drops under that threshold. PMI typically falls away automatically once your loan balance reaches 78% of the home's original value, or you can request removal at 80% once you've built enough equity, so it's usually a temporary cost rather than a permanent one. If avoiding PMI entirely matters to you, try the 20% Down quick scenario button above the inputs to see how the payment changes without it.
HOA fees
Homeowners association dues cover shared costs for a community — landscaping, amenities, building insurance for condos, and reserve funds for future repairs. HOA fees are billed directly by the association rather than through your mortgage escrow, but lenders still count them toward your monthly housing cost when qualifying you for a loan, and this calculator does the same. Dues can range from a token amount to several hundred dollars a month depending on the amenities and building type, so it's worth confirming the exact figure — and whether a special assessment is pending — before finalizing your budget.
How interest rates affect your monthly payment
Interest rate has an outsized effect on affordability because it compounds over the entire loan term, not just the amount you borrow. On a $400,000 loan, moving from 6% to 6.5% raises the monthly principal & interest payment by roughly $130 and adds tens of thousands of dollars in interest over 30 years — try the +0.5% Interest and −0.5% Interestquick scenario buttons above to see the exact difference for your own numbers. That's why the rate integration block above your inputs shows today's average rate alongside your entered rate: if your rate is noticeably above the current market, it's worth checking today's mortgage rates before locking anything in, and if you're comparing two different loan offers directly, the loan comparison calculator will show you exactly which one costs less in total. If you already have a mortgage and rates have dropped since you closed, the mortgage refinance calculator shows whether refinancing into today's rate would actually save you money after closing costs.
Should you make extra payments?
Extra principal payments reduce your balance faster, which shrinks the interest charged on every subsequent payment — a small, consistent extra amount can shave years off a 30-year loan and save a meaningful amount in total interest. The Advanced optionssection above lets you add a recurring extra monthly payment or switch to bi-weekly payments (which effectively adds one extra monthly payment per year) and see the updated payoff date and total interest immediately. The tradeoff is liquidity: money sent toward principal isn't easily recoverable if you need it later, so it's worth comparing the guaranteed return of paying down a 6-7% mortgage against other uses for that cash. For a deeper look at lump sums, payment schedules, and exactly how much extra payments save over time, the mortgage overpayment calculator is purpose-built for that comparison.
Affordability and next steps
The affordability insight card above uses a standard 28% front-end housing-cost ratio to suggest a rough household income guideline for your estimated payment — a widely used lending benchmark, not a guaranteed approval threshold. If you're still weighing whether buying makes sense at all compared to renting in your area, the rent vs buy calculator factors in the exact payment estimated here alongside opportunity cost and appreciation assumptions to help with that bigger decision.