Mortgage Amortization Calculator
See every payment, every month - and exactly how extra payments slash your total interest.
📊 What is a Mortgage Amortization Calculator?
A mortgage amortization calculator generates the complete payment schedule for a home loan - every payment, every month, showing exactly how much goes to interest, how much reduces your principal, and what the remaining balance is. Unlike a basic mortgage calculator that shows only the monthly payment, an amortization calculator reveals the full story of your loan from the first payment to the last.
Three situations where this tool is indispensable: first, before signing a mortgage - knowing you will pay $382,000 in interest on a $300,000 loan over 30 years helps you negotiate harder on the rate or consider a shorter term. Second, when evaluating extra payments - this calculator shows exactly how much interest an extra $200/month saves and how many years it trims from your loan, so you can make an informed decision versus investing the same money. Third, for tax preparation - the annual interest column matches your Form 1098 and tells you whether itemizing deductions is worthwhile.
Many borrowers are surprised to find that nearly 85% of their first mortgage payment goes to interest in year 1. The amortization schedule makes this concrete: on a $300,000 loan at 6.5%, month 1 interest = $1,625 and principal = $271. Month 360 interest = $12 and principal = $1,884. The schedule shows the entire journey between those two extremes.
This calculator supports both yearly and monthly schedule views. The yearly view condenses the schedule to one row per year - useful for long-range planning. The monthly view shows all 360 rows (for a 30-year loan) - useful for finding the exact month when your balance crosses 80% LTV (the PMI cancellation threshold) or verifying individual bank statements. Both views update instantly when you change any input.
📐 Formula
📖 How to Use This Calculator
Generating and Reading Your Amortization Schedule
💡 Example Calculations
Example 1 — Standard 30-Year Mortgage, No Extra Payments
$300,000 loan | 6.5% interest | 30-year term | no extra payment
Example 2 — Same Loan with $300/Month Extra Payment
$300,000 loan | 6.5% | 30-year term | $300 extra/month
Example 3 — 15-Year Mortgage Comparison
$300,000 loan | 6.0% | 15-year term | no extra payment
❓ Frequently Asked Questions
🔗 Related Calculators
What is a mortgage amortization schedule and why does it matter?
An amortization schedule is a complete table showing every loan payment, split between principal and interest, with the remaining balance after each payment. It matters because it reveals how much of your early payments go to interest (often 80%+) versus principal, exactly when your balance crosses key thresholds like 80% LTV for PMI removal, and the total interest you will pay over the life of the loan. Reviewing your schedule before signing gives you the full picture of the loan's true cost.
How does mortgage amortization work?
Each monthly payment covers interest on the current outstanding balance plus a portion that reduces the principal. In early months, interest is highest because the balance is highest. As principal falls, interest shrinks and more of each payment goes to principal. This process - called negative amortization's inverse - continues until the final payment clears the balance. The formula for each month's interest is: Interest = Outstanding Balance × Monthly Rate.
How much interest do I pay in the first year of a 30-year mortgage?
In year 1 of a $300,000 mortgage at 6.5%, your 12 payments total roughly $22,770. Of that, about $19,300 goes to interest and only $3,470 to principal - 85% interest, 15% principal. By year 10 the split is still about 70/30. The crossover where principal exceeds interest typically occurs around year 19 of a 30-year term.
How much can extra monthly payments save me on my mortgage?
Extra payments reduce your principal faster, which lowers future interest charges - and the savings compound every month. On a $300,000 30-year mortgage at 6.5%, an extra $200/month saves approximately $68,000 in total interest and cuts 5.5 years off the loan. An extra $500/month saves over $120,000 and cuts 10 years. Use the extra payment field in this calculator to model your exact scenario.
What is the difference between monthly and yearly amortization views?
The monthly view shows every single payment - 360 rows for a 30-year loan - with exact figures for each month's interest, principal, and remaining balance. This is useful for verifying bank statements and finding the exact month when PMI can be cancelled. The yearly view aggregates payments by year, showing annual principal paid, annual interest paid, and end-of-year balance - easier for long-term planning and tax preparation.
How do I find the month when my mortgage balance drops to 80% LTV?
Switch to the monthly view and scroll to the row where the Balance column reaches 80% of your original purchase price. For example, on a $300,000 home with a $240,000 loan (80% LTV from the start), you'd have no PMI. On a $300,000 home with $270,000 borrowed (90% LTV), search the monthly table for balance = $240,000 (80% of $300,000) to find the exact month you can request PMI cancellation.
Does making extra principal payments change my monthly payment amount?
No - your required monthly payment stays the same. Extra payments reduce the outstanding balance and future interest charges, but the bank keeps collecting the same required amount until the loan is paid off early. The benefit shows up as months eliminated from the end of your loan term and total interest saved. Some mortgages allow a formal recast (re-amortization) where the payment is recalculated on the new lower balance - check with your lender.
Is it better to make extra principal payments or invest the money instead?
This is a rate-of-return comparison. Prepaying a 6.5% mortgage is a guaranteed 6.5% after-tax return (no capital gains on interest saved). If your investments reliably return more than your mortgage rate after taxes, investing wins. Historically the stock market has averaged 8–10% annually, but with volatility and taxes. A common rule: if your mortgage rate is above 5%, prepaying is competitive; below 4%, investing is usually better. Consider your risk tolerance and tax situation.
What is negative amortization and how do I avoid it?
Negative amortization occurs when a loan payment is less than the interest due for that period, causing the outstanding balance to grow instead of shrink. This happens with some adjustable-rate mortgages, interest-only loans, or graduated-payment mortgages. Standard fixed-rate mortgages use fully amortizing payments - guaranteed to pay off in full by the last payment. Always confirm your loan is fully amortizing and avoid payment plans that allow minimum payments below the interest charge.
How is the amortization schedule affected by the loan interest rate?
The interest rate affects every row in the schedule. A higher rate means more of each payment goes to interest, leaving less for principal, which means the balance falls slowly and total interest paid is much higher. On a $300,000 30-year loan: at 5% total interest = $279,767; at 6.5% total interest = $382,633; at 8% total interest = $493,433. Each 1.5% rate increase adds roughly $100,000+ in total interest on a $300,000 loan.
Can I use this amortization schedule for tax purposes?
Yes. The interest column shows exactly how much mortgage interest you paid in each month and year. Sum the interest column for any calendar year to get your annual mortgage interest deduction figure, which should match Form 1098 from your lender. US homeowners can deduct mortgage interest on loans up to $750,000 if they itemize deductions. Keep in mind that the standard deduction doubled in 2017 - many homeowners no longer benefit from itemizing.