Mortgage Calculator
Monthly payment, amortization schedule, PMI, extra payments, refinance break-even
How to Use This Mortgage Calculator
Enter Your Loan Details
Start by entering the home price and your down payment — either as a dollar amount or percentage. A 20% down payment avoids PMI (private mortgage insurance) and is the standard benchmark. Enter the interest rate you've been quoted or use current market rates to estimate. Choose your loan term: 30-year loans have lower monthly payments but cost more in interest; 15-year loans save significantly on interest but require higher monthly payments.
Add Taxes, Insurance, and PMI
Expand the "Taxes, Insurance & PMI" section for a complete payment picture. Property tax varies widely by location — the national average is about 1.1% of home value annually. Home insurance typically costs $1,000–$2,000 per year. If your down payment is below 20%, you'll pay PMI (usually 0.5–1.5% annually) until your loan balance reaches 80% of the original home value.
Model Extra Monthly Payments
The "Extra Monthly Payment" field shows the dramatic impact of paying more than the minimum. Even an extra $200/month on a $400,000 loan at 7.5% saves over $80,000 in interest and cuts 6+ years off a 30-year mortgage. The calculator shows your exact interest savings and new payoff date in the green summary box.
Read the Amortization Schedule
The amortization table breaks down every monthly payment into principal (what reduces your balance) and interest (what you pay the lender). Early payments are mostly interest — on a 30-year loan at 7.5%, less than 30% of your first payment goes to principal. As years pass, the ratio flips. The schedule makes this visible so you can see exactly when you build significant equity.
When to Refinance
Use the Refinance Calculator to determine your break-even point — the number of months until your accumulated monthly savings exceed your closing costs. Refinancing generally makes sense if you can lower your rate by at least 0.5–1%, you plan to stay in the home for several years, and the break-even point is within your expected stay. Rates move daily; even a 1% rate reduction on a $350,000 loan saves over $200/month.
Frequently Asked Questions
How is a monthly mortgage payment calculated?
Your monthly P&I payment uses the standard amortization formula: M = P × [r(1+r)^n] / [(1+r)^n−1], where P is loan principal, r is monthly interest rate, and n is number of payments.
What is PMI and when can I remove it?
PMI (Private Mortgage Insurance) is required when your down payment is less than 20% (LTV > 80%). It typically costs 0.5–1.5% of the loan per year. Once your balance falls to 80% of the original home value, PMI can be removed.
How much can extra monthly payments save?
Even $100–$200 extra per month on a 30-year loan can save tens of thousands in interest and cut years off the loan. Use the Extra Monthly Payment field to see your exact savings.
When does refinancing make sense?
Refinancing is worthwhile when you can lower your rate by at least 0.5–1%, you plan to stay in the home past the break-even point (typically 2–4 years), and closing costs are covered by your monthly savings.
What is loan-to-value (LTV) ratio?
LTV is your loan amount divided by the home's value. A 20% down payment gives an 80% LTV. LTV affects PMI requirements, interest rates, and refinance eligibility.
What's the difference between interest rate and APR?
The interest rate is what you pay on the loan balance. APR (Annual Percentage Rate) includes fees and other costs, making it the true cost of the loan. Our calculator uses the interest rate for payment calculations.