Amortization Calculator: Payment Schedule
Calculate monthly loan payments and view a year-by-year amortization schedule showing principal and interest breakdown for any loan amount.
What Is the Amortization Calculator?
The Amortization Calculator computes your monthly loan payment and generates a complete year-by-year schedule showing exactly how each payment is split between principal repayment and interest charges. This schedule (called an amortization table) reveals the mechanics of how loan balances decline over time and how much of each payment actually builds equity versus costs.
Amortization is the process of paying off a loan through regular, equal payments over a fixed schedule. Each payment covers that period's interest first, with the remainder applied to reduce the principal balance. Early in a loan's life, the vast majority of each payment goes to interest; over time, as the principal shrinks, an increasing portion of each payment reduces what you owe. This is why the total interest you pay on a 30-year mortgage can exceed the original loan amount.
An amortization calculator provides the detailed picture for any fixed-rate loan: mortgages, auto loans, personal loans, or any other installment loan regardless of size or term.
Key Features
Monthly Payment Calculation The calculator computes your monthly payment using the standard annuity formula, which accounts for loan amount, annual interest rate, and loan term. The monthly payment stays constant throughout the loan; what changes is the proportion going to principal versus interest.
Total Payment and Total Interest Summary Beyond the monthly payment, the calculator shows your total payment over the life of the loan (monthly payment × number of payments) and the total interest paid. The difference between total payment and the original loan amount is your total interest cost (often a striking number that motivates extra payments).
Year-by-Year Amortization Table The full amortization schedule breaks down each year of the loan, showing the interest paid that year, the principal paid that year, and the remaining balance at year-end. This makes it easy to see when your loan crosses key milestones: 25%, 50%, or 75% of principal paid down.
Works for Any Loan Type The amortization calculator applies equally to mortgages, auto loans, personal loans, student loans, and any other fixed-rate installment loan. The math is identical regardless of loan purpose.
How to Use the Amortization Calculator
Step 1: Enter Loan Basics
Input the loan amount (the principal you are borrowing), the annual interest rate, and the loan term in years. For a typical 30-year mortgage at 7% interest on a $300,000 loan, enter those three numbers.
Step 2: Calculate
Click calculate to see your monthly payment, total amount paid over the loan life, and total interest. Then scroll to the amortization table to see the year-by-year breakdown.
Step 3: Analyze the Schedule
Look at the amortization table to understand how your balance declines over time. Notice how much interest you pay in the early years versus the later years. This helps you understand the value of extra payments: even modest additional principal payments early in a loan's life save substantial interest over the full term.
Practical Examples
Example 1: 30-Year Mortgage $350,000 loan at 7.25% for 30 years. Monthly payment: $2,389. Total paid: $860,040. Total interest: $510,040 (nearly 1.5 times the original loan amount). In year 1, approximately $25,200 of payments goes to interest and only $3,500 to principal. By year 25, the ratio reverses: more than half of each payment reduces principal.
Example 2: Auto Loan Comparison A $35,000 car loan: Compare 48 months at 6.5% vs 72 months at 7.0%. The 48-month option: $831/month, total interest $4,888. The 72-month option: $594/month, total interest $7,768. The lower monthly payment costs $2,880 more in total interest, useful data when deciding between loan terms.
Example 3: Personal Loan $15,000 personal loan at 11% for 5 years. Monthly payment: $326. Total paid: $19,560. Total interest: $4,560. The amortization table shows the balance falls below $10,000 approximately 28 months into the loan, useful for planning a potential payoff.
Tips and Best Practices
Make Extra Principal Payments When Possible Additional payments applied directly to principal reduce your balance faster, shortening the loan term and reducing total interest. Even one extra payment per year on a mortgage can shave years off the loan. Many online calculators can model the impact of extra payments; use this amortization schedule as a baseline.
Understand the Early-Payment Interest Heavy Period Most people are surprised to discover how little principal their early mortgage payments reduce. In a 30-year mortgage, it typically takes until year 18-20 before you are paying more principal than interest monthly. This explains why refinancing or selling early in a loan captures less equity than many people expect.
Use the Table When Comparing Loan Terms When deciding between a 15-year and 30-year mortgage, or 48-month and 60-month auto loan, run both scenarios in the amortization calculator. The higher payment of the shorter term builds equity much faster and costs significantly less in total interest; concrete numbers help make this tradeoff visible.
Consider Biweekly Payments Many lenders allow biweekly payments (paying half the monthly payment every two weeks). Because there are 26 biweekly periods per year, you effectively make 13 monthly payments instead of 12, reducing your loan term by approximately 4-5 years on a 30-year mortgage with no change in your individual payment amount.
Use the Schedule to Time Major Decisions If you are considering refinancing, the amortization table shows your remaining balance at any point in the loan. This helps you calculate whether the interest rate reduction from refinancing offsets the new closing costs, especially important if you are refinancing several years into a loan.
Common Issues and Troubleshooting
My actual payment is slightly different from the calculator Small differences can arise from rounding conventions (cents rounding), how your lender handles the first partial month of interest, and whether your loan includes escrow for taxes and insurance. The calculator computes the pure principal-and-interest payment; your actual statement may include escrow components.
The interest rate to use: APR or note rate? Enter the note rate (the stated annual interest rate on the loan), not the APR. APR includes fees and other costs expressed as an annual rate, which would inflate your calculated payment. The note rate gives you the pure P&I calculation.
I want to calculate the impact of extra payments This calculator shows the standard amortization without extra payments. To model extra payments, use the result as a baseline (your current balance at any point in the table) and run a new calculation treating the current balance as the loan amount with the remaining term.
My loan has a balloon payment Standard amortization calculators assume full amortization to zero balance. If your loan has a balloon payment, the monthly payments are typically calculated on a longer amortization period, and the final payment differs. This calculator reflects full-amortization loans.
Privacy and Security
The Amortization Calculator processes all calculations in your browser. No loan amount, interest rate, or personal financial information is transmitted to any server. No account is required and no data is retained.
Frequently Asked Questions
What is amortization? Amortization is the process of gradually paying off a debt through regular, scheduled payments. Each payment covers interest charges first, with the remaining amount reducing the principal balance. Over time, as the principal decreases, less interest accrues, and a larger portion of each payment goes to principal.
Why do I pay so much interest early in the loan? Because interest is calculated on the outstanding balance. Early in the loan, the balance is highest, so interest charges are highest. As you pay down principal, the balance falls, reducing the interest portion of each subsequent payment.
What is the difference between amortization and depreciation? Amortization typically refers to the repayment of debt (as calculated here) or the expense recognition of intangible assets. Depreciation refers to the expense recognition of tangible assets. Both spread costs over time, but they apply to different contexts.
Can I pay off my loan early? Most fixed-rate loans allow prepayment without penalty, though some mortgage loans have prepayment penalty provisions (particularly certain non-QM and subprime loans). Check your loan agreement before making extra payments to confirm prepayment terms.
How do I calculate the payoff amount at a specific month? Your payoff amount at any month equals the remaining balance shown in the amortization table for that period, plus any accrued interest since the last payment date. Contact your lender for an exact payoff quote, which will include per-diem interest.
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