Monthly payments, total interest, amortization.
Monthly payments, total interest, amortization.
Enter the home purchase price, your planned down payment, the annual interest rate your lender quoted, and your preferred loan term. Hit Calculate to instantly see three key numbers: your fixed monthly payment, the total interest you'll pay over the life of the loan, and a complete amortization breakdown showing how each payment splits between principal and interest.
The calculator uses the standard fixed-rate amortization formula. In the early years, the majority of each payment goes toward interest โ not principal. As the balance shrinks, more of each payment chips away at the loan itself. This is why extra payments in year 1โ5 save dramatically more interest than extra payments in year 20.
Your monthly mortgage payment (principal + interest) is just one part of your true housing cost. Most lenders collect three additional costs in the same payment via an escrow account:
Add these to your P&I number for a realistic picture of what you'll actually owe each month.
Even small rate changes have enormous effects over a 30-year term. On a $350,000 loan, the difference between a 6.5% and 7.5% rate is about $214/month โ but over 30 years, that's nearly $77,000 in additional interest paid. This is why improving your credit score before applying can be one of the highest-return financial moves you make. Moving from a 680 credit score to a 740 can drop your rate by 0.5โ0.75%, easily saving $40,000โ$60,000 on a typical mortgage.
The 30-year mortgage dominates because of its lower monthly payment โ but the 15-year version wins on total cost by a wide margin. On a $300,000 loan at current rates, a 15-year mortgage might cost $2,100/month vs $1,800 for a 30-year โ a $300 difference. But the 30-year borrower pays roughly $180,000 more in interest over the life of the loan. If you can comfortably handle the higher 15-year payment, the long-term savings are substantial.
PMI protects the lender if you default when your equity is below 20%. You can request removal once you reach 20% equity through payments or appreciation. Under the Homeowners Protection Act, lenders must automatically cancel PMI when you reach 22% equity based on your original amortization schedule.
If your mortgage rate is above 5โ6%, extra principal payments deliver a guaranteed return equal to your interest rate โ often better than a savings account. Even one extra payment per year on a 30-year mortgage can cut 4โ6 years off the loan and save tens of thousands in interest.
Conventional loans typically require a minimum 620 score, but you'll get the best rates with 740+. FHA loans accept scores as low as 580 with 3.5% down. The higher your score, the lower your rate โ and the lower your rate, the more house you can afford.
Conventional loans require as little as 3% down, FHA loans 3.5%, and VA/USDA loans can be 0% down for qualified buyers. However, putting down less than 20% means paying PMI. A 20% down payment eliminates PMI and lowers your monthly cost significantly.