Free Mortgage Calculator
See exactly what a home loan costs before you sign. Monthly payment, total interest, and payoff details — calculated instantly.
Your loan at a glance
How to use the mortgage calculator
- Enter the loan amount — your home price minus the down payment.
- Enter the annual interest rate from your loan estimate or pre-approval letter.
- Set the loan term. Thirty years is standard in the US; fifteen-year loans cost much less in interest but demand higher payments.
Understanding your mortgage
Your monthly payment is calculated with the standard amortization formula, which spreads the loan evenly across every month of the term. Early on, most of each payment goes toward interest rather than principal — that is why the "interest in first year" figure can look startling. Over time the balance flips, and later payments chip away mostly principal. Two numbers matter more than anything else: the interest rate and the term. Dropping your rate by half a point on a $350,000 loan can save tens of thousands of dollars over 30 years, which is why shopping multiple lenders is worth the effort. And while a 15-year term roughly doubles the monthly payment, it typically cuts total interest by two-thirds or more. Note that this calculator covers principal and interest only — your real monthly housing cost also includes property tax, homeowner's insurance, and possibly PMI or HOA dues, so always budget beyond the number shown here.
Frequently asked questions
Does this include property tax and insurance?
No — this covers principal and interest only. As a rough rule, add 1–2% of the home's value per year for property tax plus your homeowner's insurance premium to estimate the true monthly cost.
Is a 15-year or 30-year mortgage better?
A 15-year loan builds equity fast and slashes total interest, but the monthly payment is much higher. A 30-year loan costs more overall but keeps payments manageable and flexible. Run both terms here to compare.
How is the monthly payment calculated?
With the standard amortization formula: M = P × r(1+r)^n ÷ ((1+r)^n − 1), where P is the loan amount, r the monthly rate, and n the number of payments.
Do extra payments really help?
Yes. Even one extra full payment per year on a 30-year loan can shave several years off the term and save a large chunk of interest, because extra money goes straight to principal.