Free Online Mortgage Calculator
Quick answer: A $400,000 home with 20% down at 6.5% interest over 30 years costs about $2,023 per month in principal and interest — with roughly $408,000 in total interest over the life of the loan. Our free mortgage calculator works out your exact monthly payment, total interest, payoff date, and a year-by-year amortization schedule for any price, down payment, rate, and term — instantly and privately, right in your browser.
A $400,000 home with 20% down at 6.5% interest over 30 years costs about $2,023 per month in principal and interest — with roughly $408,000 in total interest over the life of the loan. Our free mortgage calculator works out your exact monthly payment, total interest, payoff date, and a year-by-year amortization schedule for any price, down payment, rate, and term — instantly and privately, right in your browser.
How to Use the Mortgage Calculator
- Enter the home price and your down payment — the loan amount is the difference.
- Set your annual interest rate and pick a loan term (30, 20, 15, or 10 years).
- Optionally add an extra monthly payment to see how fast you could pay the loan off early.
- Click Calculate Payment for your monthly principal & interest, total interest, payoff date, and the full amortization table.
Why Use Our Mortgage Calculator?
- True monthly payment — principal & interest computed with the standard amortization formula lenders use.
- Year-by-year amortization table — see exactly how each payment splits between principal and interest.
- Extra-payment modeling — add $100–$500/month and watch years of interest disappear.
- Term comparison — switch between 30, 20, 15, and 10-year terms to compare total interest instantly.
- 100% private — every calculation runs locally in your browser; your finances never leave your device.
Frequently Asked Questions
How is my monthly mortgage payment calculated?
With the standard amortization formula: M = P × r(1+r)ⁿ ÷ ((1+r)ⁿ − 1), where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the number of payments. Our calculator uses this exact formula, so its principal & interest figure matches what a lender quotes.
Does this include property taxes and insurance?
No — this calculator covers principal and interest (P&I) only. Most homeowners also pay property tax and homeowner's insurance each month, often bundled into escrow (together called PITI). Add your local tax and insurance estimates on top of the P&I figure for your true monthly housing cost.
Is a 15-year or 30-year mortgage better?
It depends on your budget. On a $320,000 loan at 6%, a 30-year term costs about $1,919/month in P&I with roughly $371,000 in total interest; a 15-year term costs about $2,700/month but only about $166,000 in total interest — saving over $200,000. The 15-year builds equity far faster, but the higher payment leaves less room in your budget.
What is amortization, and why is my early payment mostly interest?
Amortization is the gradual payoff schedule of the loan. Because interest is charged on the remaining balance, early payments are interest-heavy: in year one of a $320,000 loan at 6.5%, about $20,695 of your payments goes to interest and only about $3,577 reduces the principal. The split flips as the balance shrinks — check the table above.
What is PMI and when do I pay it?
Private mortgage insurance (PMI) is usually required on conventional loans when your down payment is under 20%. It typically costs 0.5%–1.5% of the loan amount per year, added to your monthly payment, and generally drops off once you reach 20% equity. This calculator's payment figure excludes PMI.
How accurate is this estimate?
The principal & interest math is exact — it is the same formula lenders use, so the P&I payment matches to the cent. Your final quoted payment will differ because of property taxes, insurance, PMI, and closing costs, which vary by location and lender. Use this as a planning figure and confirm with a lender's Loan Estimate.
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