Mortgage Calculator
Estimate your monthly mortgage payment, full PITI cost, and total interest from the home price, down payment, rate, and term.
- Free, no account
- No watermark
- No usage limit
About the Mortgage Calculator
Your lender cares about exactly one number, the monthly payment, because that's the figure they underwrite you against. So that's the number every free calculator pushes at you first. It's also the least interesting number about your mortgage. The one that decides whether you keep an extra six figures or hand it to the bank is total interest, and most of the popular calculators talk about attacking it without ever computing what happens when you do, so this one runs the arithmetic instead.
Take a normal case. A $400,000 home, 20 percent down, so a $320,000 loan at 6.5 percent over 30 years. Monthly principal and interest lands around $2,023, and that's the number a loan officer quotes you. What they don't put next to it: across those 30 years you'd pay roughly $408,000 in interest, more than the house you borrowed for. Now add $200 a month straight at the principal. You'd be free about six years early and keep well over $100,000. Same home, same rate, one change, and the tool gives you the exact figure for your own inputs.
Everything runs in your browser. Nothing you type leaves your device, and there's no account or email wall, unlike the calculators that make you hand over an email before they'll show the result, then pass your details to a lender who follows up whether you asked or not. Nudge the rate a quarter point and the payment moves while you type.
How to use
- Enter the home price and your down payment. Flip the down field between percent and dollars with the % and $ buttons, whichever you already know.
- Put in the interest rate (the APR your lender quoted) and choose a term. Tap the 15, 20, or 30 preset, or type any number of years. A rate of 0 works and just spreads the loan evenly.
- Want your true monthly cost instead of just the loan slice? Open "Add taxes, insurance, PMI and HOA" and fill in what applies to you. Skip it for plain principal and interest.
- Now the section that changes the total. Open "Pay it off faster" and model extra money against the loan: extra each month, a lump once a year, a one-time payment today, or the biweekly checkbox. Add a loan start date for real calendar payoff dates.
- Read the results underneath. You get the monthly payment, total interest, a green savings box the moment you add extra, and a full amortization schedule you can switch between year and month view and download as a CSV.
Every field is live, so scenarios are instant. Another five percent down, 15 years instead of 30, an extra $300 a month, the answer's already sitting there before you finish typing.
The number your loan officer won't lead with
Total interest is where the money actually is, and one lever moves it more than any other: extra principal, paid early. To see why, look at how a payment splits. In month one on that $320,000 loan, your $2,023 payment is about $1,733 pure interest and only around $290 knocking down what you owe. Interest is charged on whatever you still owe, and early on that is nearly the whole loan, which is why almost all of an early payment disappears into interest and barely any of it touches the balance. The payment itself never changes across 30 years. What changes is the split inside it, and it takes years before the two even out.
That's the whole reason timing matters so much. A dollar of extra principal in year one avoids almost 30 years of compounding interest, while the same payment in year 25 saves only about five years of it. So an extra $200 early is worth far more than the same amount paid later. The calculator shows the year-by-year interest-versus-principal breakdown, so you can watch exactly when the two even out and how much a bit of extra changes it. If you're going to attack the loan, front-load it.
When paying extra is the wrong move
Aggressive payoff isn't automatically the smart play, and anyone who tells you it always is has stopped doing the math. If your mortgage sits at 4 percent and you could reasonably earn 7 to 8 percent investing the same money, investing wins over the long run, and that opportunity cost is a real number rather than a talking point. The compound interest calculator will show you what that money does left to grow instead.
Two more things before you throw cash at the balance. Check the loan for a prepayment penalty. Most modern mortgages don't have one, but some charge a fee for paying ahead in the first few years, so read the paperwork. And don't drain your safety net to do it. A mortgage you've paid down is illiquid, you can't eat a kitchen. Clear high-rate debt like credit cards first, keep an emergency fund, then send the extra. For a lot of people the honest answer is a bit of both, a modest guaranteed-return payment against the loan and the rest kept liquid.
Frequently asked questions
Does paying biweekly really pay off a mortgage faster?
Yes, and it's simple arithmetic. Half your payment every two weeks means 26 half-payments a year, which adds up to 13 full payments instead of 12, and that spare one goes straight to principal. Whether it works comes down to your lender. Some don't apply biweekly payments to principal as they arrive, they just park the halves and pay monthly, which gets you nothing, and a few charge a setup fee for the privilege. Easiest fix: skip their program and send the same extra yourself as a monthly principal payment. Same result, no middleman.
What's the difference between recasting and just paying extra?
They both use a lump sum but do opposite things to your payment. A recast re-amortizes the loan over the same remaining term after you pay a chunk down, so your required monthly payment drops while the payoff date stays put. Extra payments keep the payment the same and pull the payoff date closer instead. Recasting buys breathing room in your budget, extra payments buy time and interest savings. This calculator models the extra-payment route. A recast usually runs a small fee and you have to ask the lender for it.
When does PMI actually go away?
You'll pay private mortgage insurance whenever your down payment is under 20 percent, and it protects the lender, not you. You can request cancellation once you've paid the balance down to 80 percent of the home's original value, and by law it auto-cancels at 78 percent. The gotcha is "original value," today's higher price doesn't count unless you pay for a fresh appraisal to prove it. In the tool, PMI only appears while your down payment is below 20 percent. If you're just short, the down payment calculator shows how much more cash clears that line.
Should I take a 15-year or a 30-year loan?
Fifteen-year loans carry a lower rate and cost far less interest overall, but the monthly payment is a lot steeper because you're compressing the payoff into half the time. The move most people overlook: take the 30-year for its low required payment, then pay it like a 15 whenever cash allows. You get the safety of a smaller mandatory bill in a tight month and most of the interest savings when things are good. Plug both terms into the calculator with your real rate and weigh the monthly against the total interest.
Why does my "fixed" payment keep creeping up?
If your lender escrows your taxes and insurance, the principal and interest genuinely never move, but the escrow slice does. Property gets reassessed, premiums rise, and your total payment drifts up year to year even on a fixed-rate loan. It surprises people who were promised a fixed payment and then watch it climb. The calculator splits tax and insurance into a monthly figure so you can see how big that moving part is next to the loan itself.
Is the math accurate, and is my data private?
The principal-and-interest math is exact, it's the standard amortization formula every US lender uses. The add-ons (tax, insurance, PMI, HOA) are only as good as the numbers you enter, so use real quotes for a close result rather than guesses. All of it happens in your browser, and nothing you type is sent anywhere, it keeps working offline once the page has loaded, and there's no sign-up. Your last set of figures is kept on this device, so the taxes, insurance and PMI are already filled in when you come back to try another rate. This one's built for a home loan. For a car or personal loan the loan calculator runs the same engine without the mortgage extras.