Mortgage Calculator
Understanding Your Mortgage Payment
Buying a home is the largest purchase most people ever make, and the monthly payment shapes your budget for decades. The calculator above estimates that payment using standard amortization — the same math your lender uses — so you can see what a given home price, interest rate, and loan term actually translate to before you ever sit down with a lender.
Three numbers drive the result: the loan amount (the home price minus your down payment), the interest rate, and the term, which for most mortgages is 15 or 30 years. Adjust any of them in the calculator and watch how the payment and the total interest move. That total interest figure is the one most people overlook — and it's often the most eye-opening number on the page.
What "principal and interest" means — and what it leaves out
This calculator shows your principal and interest payment: the core cost of borrowing the money and paying it back. That's the figure people usually mean when they ask "what's the mortgage payment?" But your actual monthly housing cost is typically higher, because most homeowners also pay property taxes, homeowners insurance, and — if the down payment is under 20% — private mortgage insurance (PMI). Lenders bundle these into what's called a PITI payment (Principal, Interest, Taxes, Insurance). Use this calculator to understand the loan itself, then add estimates for taxes and insurance to see your true monthly cost.
Why the interest rate matters so much
On a loan this large and this long, a small change in rate has an enormous effect. Try it above: take the same home price and term, then compare a rate one percentage point higher. The monthly payment rises by a noticeable amount — and over 30 years, the total interest can differ by tens of thousands of dollars. This is why locking a good rate, and improving your credit before you apply, pays off more on a mortgage than on almost any other loan.
15-year vs. 30-year: the real tradeoff
The 30-year mortgage is the default in the U.S. because it keeps the monthly payment low and affordable. The 15-year mortgage carries a higher monthly payment but a lower interest rate and far less total interest, because you're paying the loan off in half the time. Run both in the calculator. A 30-year loan is easier on your monthly budget; a 15-year loan can save a six-figure sum in interest over its life. Neither is "right" — it depends on whether your priority is monthly breathing room or long-term savings.
How your down payment changes everything
A larger down payment shrinks the loan amount, which lowers your monthly payment and reduces total interest. Crossing the 20%-down threshold has an extra benefit: it usually lets you avoid PMI, which can save you a meaningful amount each month. Even a modest increase in down payment can change your payment more than you'd expect — test a few amounts in the calculator to see the effect.
Common questions
Why is the lender's quote higher than the calculator? Because the calculator shows principal and interest only. A lender's monthly figure often includes property taxes, insurance, and PMI, plus any escrow the lender collects. The calculator gives you the loan math; the lender's estimate gives you the all-in housing cost.
What credit score do I need for a good rate? There's no single cutoff, but higher scores generally earn lower rates. Because rate has such a large effect over 30 years, improving your credit before applying — even by a tier — can be one of the highest-value financial moves you make before buying.
Should I pay points to lower my rate? "Points" are upfront fees you pay to reduce your interest rate. Whether they're worth it depends on how long you'll keep the loan: the longer you stay, the more a lower rate pays off. The calculator can help you compare the monthly payment at different rates so you can weigh the tradeoff.
Does paying extra toward the mortgage help? Yes, significantly. Because early payments are mostly interest, extra money applied to principal early in the loan removes a large amount of future interest and can shave years off the term. Confirm there's no prepayment penalty and that extra payments are applied to principal.
Is it better to put down more or invest the cash instead? That's a personal tradeoff between guaranteed savings (less interest paid) and potential investment returns, and it depends on your rate, your goals, and your risk tolerance. The calculator shows you the interest side of that equation clearly so you can weigh it against your other options.
This guide is for educational purposes only and is not financial, tax, or legal advice. Mortgage terms, rates, taxes, and insurance costs vary by lender, location, and individual circumstances. Consult a qualified mortgage or financial professional before making home-buying decisions.