Loan Amortization Calculator (USA)
Estimate your fixed monthly P&I payment, total interest paid, and exact payoff date — with a full amortization schedule and the impact of extra monthly principal payments.
| # | Month | Payment | Principal | Interest | Balance |
|---|---|---|---|---|---|
| Calculate to see schedule | |||||
Every 12th row (start of year) is highlighted in blue. PDF export includes the complete schedule.
How to Use the Amortization Calculator
Getting your full loan picture takes under 60 seconds. Enter three numbers, adjust the optional extra payment field, and the calculator instantly generates your complete amortization schedule — payment by payment, all the way to payoff.
Enter Your Loan Amount
Type the total amount you are borrowing — not the home price. If you’re purchasing, subtract your down payment from the purchase price to get the loan amount. If you already have a mortgage and are modelling payoff scenarios, enter your current outstanding balance.
Select Your Term & Rate
Choose your loan term from the dropdown (30, 20, 15, or 10 years) or select Custom to type any term. Enter your annual interest rate — use the range slider to quickly model different rate scenarios from 2% to 12%. Rate changes update the schedule instantly so you can compare scenarios side by side.
Add an Extra Monthly Payment (Optional)
Enter any extra amount you plan to add to your principal each month. A green savings badge instantly appears showing how much interest you’ll save and how many years earlier you’ll pay off the loan. Try $100, $200, or $500 to see the compounding impact. This is one of the most powerful fields in the calculator.
Review Your Schedule & Download PDF
See your monthly P&I, total interest, payoff term, and interest saved in the results panel. Expand the full amortization schedule accordion to view every payment — each row shows the split between principal and interest, with year starts highlighted. Download the multi-page PDF to share with your lender or financial advisor.
What This Amortization Calculator Covers
More than a simple payment calculator — this tool gives you the complete picture of your loan from the first payment to the last, including the compounding impact of extra principal payments.
Complete Month-by-Month Schedule
Every single payment is listed in the expandable accordion table — month number, date, total payment, principal portion, interest portion, and remaining balance. Year-start rows are highlighted in blue for easy scanning. The full schedule is included in the PDF export.
Extra Payment Impact Analysis
Model any extra monthly principal payment and instantly see the interest saved, time saved, and new payoff date compared to the standard schedule. A live savings badge appears above the extra payment field as you type, so you always see the impact in real time without scrolling down.
Interactive Rate Slider
The interest rate field includes a range slider from 2% to 12%, letting you sweep through rate scenarios without typing. This makes it easy to model the difference between a 6.0% and 7.0% rate on the same loan — seeing the difference in monthly payment and total interest at a glance.
Flexible Term Options (Custom Supported)
Choose from 30, 20, 15, or 10-year presets, or select Custom to enter any term in years. This makes the calculator usable for non-standard loans — 7/1 ARM fixed periods, bridge loans, HELOCs with fixed repayment periods, and any loan with a term that doesn’t fit a standard dropdown.
Balance Trajectory Line Chart
A filled area line chart shows your outstanding balance declining annually from origination to payoff. Hover over any point for the exact balance at that year. For loans with extra payments, the chart visibly steepens — making the acceleration immediately clear without reading numbers.
Multi-Page PDF with Full Schedule
The downloadable PDF includes a v2-design header, hero payment card, 2-column loan details table, total cost proportion bars, 6 summary cards, and the complete amortization schedule as an autoTable — formatted across as many pages as needed, with every year-start row highlighted in blue.
What Amortization Really Costs U.S. Borrowers
How Different Borrowers Use This Calculator
Whether you’re deciding on a loan term, planning extra payments, or evaluating a refinance, here’s how to get the most out of this tool for your specific situation.
New Homebuyer
15 vs. 30-year decisionYou’re choosing between a 15-year and 30-year mortgage and want to understand the true trade-off — not just the monthly payment difference, but the total interest cost over the life of each loan. The numbers are often more dramatic than buyers expect.
- Enter your loan amount, then run the calculation once on 30 years and once on 15 years at the same rate to compare total interest directly
- Check if the 15-year payment fits within 28% of your gross monthly income — use the DTI Calculator to confirm
- If the 15-year payment is too high, try the 20-year option as a middle ground that still saves significant interest over 30 years
- Download both PDF reports and share them with your loan officer to show you’ve modelled both scenarios
Extra Payment Planner
Accelerated payoff strategyYou already have a mortgage and want to understand exactly how much faster and cheaper you can pay it off by adding a fixed extra payment each month. You want concrete numbers — not vague advice about “paying extra when you can.”
- Enter your current outstanding balance (not the original loan amount) as the loan amount, and your remaining months as a custom term
- Try $100 increments in the extra payment field — watch the savings badge update instantly as you type
- Find the “crossover point” — the extra payment amount where total interest drops below your original loan balance (a psychologically satisfying milestone)
- Use the full amortization table to identify the exact month and year you’ll make your final payment with extra payments in place
Refinance Evaluator
Break-even analysisYou’re considering refinancing your current mortgage and want to compare the amortization schedules of your existing loan against the proposed new loan — to understand whether the total interest savings justify the closing costs and reset term.
- Run the calculator once for your current loan (remaining balance, remaining months, current rate) to get your current total remaining interest
- Run it again for the proposed refinance (new balance including rolled-in closing costs, new rate, new term) to get the new total interest
- Compare the two totals — the difference tells you whether you’re actually saving money over the full life of the loan, not just per month
- Use the Refinance Calculator for a dedicated break-even date calculation that also factors in monthly savings vs. closing cost payback period
7 Strategies to Pay Off Your Mortgage Faster and Save on Interest
Your amortization schedule is not fixed. These seven proven strategies let you reduce the total interest you pay — without refinancing — and can save tens of thousands of dollars over the life of a typical mortgage.
Make One Extra Payment Per Year
Making 13 payments per year instead of 12 — either as a lump sum in January or by adding 1/12 of your P&I to each monthly payment — is one of the simplest acceleration strategies. On a typical $300,000 30-year mortgage at 6.5%, making one extra annual payment reduces the term by about 4 years and saves roughly $50,000 in interest.
Round Up Your Monthly Payment
If your P&I is $1,847, round up to $1,900 or $2,000 every month. Rounding up by even $50–$100 per month consistently adds up to significant principal reduction over the life of a 30-year loan. Use this calculator’s extra payment field to model any round-up amount — you’ll be surprised how quickly it compounds.
Apply Windfalls Directly to Principal
Tax refunds, bonuses, inheritances, and proceeds from selling assets can all be applied as lump-sum principal payments. Unlike regular extra payments (modelled in this calculator), lump sums immediately reduce your balance and all subsequent interest calculations. Even a single $5,000 principal payment in year one of a 30-year mortgage saves more than $15,000 in total interest.
Switch to Bi-Weekly Payments
Paying half your monthly payment every two weeks results in 26 half-payments per year — the equivalent of 13 full monthly payments instead of 12. Many servicers offer this as a formal program, or you can simply add 1/12 of your monthly payment as extra principal each month, achieving the same effect without a special program or fees.
Recast Instead of Refinancing After Large Paydown
If you’ve made a large lump-sum principal payment, some lenders offer a loan recast — re-amortizing the remaining balance over the remaining term, which lowers your required monthly payment without the closing costs of a refinance. Unlike refinancing, recasting keeps your existing interest rate and doesn’t restart your term clock. Ask your servicer if your loan is eligible.
Always Specify “Principal Only” When Paying Extra
When making extra payments, always explicitly designate the payment as “principal only” with your loan servicer — either online, on the check memo, or in writing. Without this designation, servicers may apply the extra amount to future monthly payments (prepaid payments) rather than reducing your principal balance, which eliminates the interest-saving benefit entirely.
Use the Amortization Schedule to Plan Your Optimal Payoff Year
Expand the full amortization schedule in this calculator and find the year at which your monthly interest drops below your monthly principal — the “crossover point.” Paying off the loan before this point saves proportionally more interest. The crossover typically occurs around year 18–20 on a 30-year mortgage — earlier than most borrowers expect. Use this knowledge to set a specific payoff target date.
Amortization Calculator — FAQ
The most common questions U.S. borrowers ask about loan amortization — answered clearly.
On a $300,000 loan at 6.5% APR: the 30-year monthly P&I is about $1,896 with total interest of ~$382,000, while the 15-year monthly P&I is about $2,613 with total interest of only ~$170,000 — saving over $210,000 in interest. Use this calculator to run both scenarios with your specific numbers.
Adding $200/month extra saves approximately $60,000 in interest and pays off the loan about 5 years early.
Adding $500/month extra saves over $100,000 and cuts roughly 8 years off the term.
Enter your own number in the extra payment field above to see your exact scenario.
If you want to formally reduce your required monthly payment, you would need to refinance — or request a loan recast if your lender offers it. A recast re-amortizes the remaining balance over the remaining term, lowering the monthly minimum without the full cost of a refinance. Not all lenders offer recasting — ask your servicer.
Important disclaimer: All calculations provided by this tool are for educational and estimation purposes only and do not constitute financial, legal, or mortgage advice. Monthly payment and amortization figures are based on standard fixed-rate amortization formulas and assume a constant interest rate, no origination fees, and no changes in payment amounts. Actual loan payments may differ due to prepaid interest, escrow requirements, rounding policies, and lender-specific terms. Results shown do not account for adjustable-rate changes, refinancing costs, or tax implications of mortgage interest. Always consult a licensed mortgage lender or financial advisor before making any financial decisions. HomeExpertly is not a lender, broker, or financial advisor.