Amortization Calculator

How to Use This Amortization Calculator

This free amortization calculator helps you understand exactly how your loan payments break down over time. Whether you have a mortgage, car loan, or personal loan, follow these steps to get a full picture of your repayment journey.

Step 1 Enter Your Loan Details

Start by entering the total loan amount you plan to borrow. Next, input the annual interest rate your lender has quoted you. Then select the loan term, which you can specify in either years or months. For a standard 30-year mortgage, enter 30 years. For a 5-year car loan, enter 5 years or 60 months.

Step 2 Add Extra Payments (Optional)

If you plan to make extra payments toward your loan, enter them in the optional section. You can specify a recurring monthly extra payment and a one-time lump sum payment at a specific month. The calculator will show you exactly how much interest you save and how many months earlier you can pay off the loan.

Step 3 Review Your Results

After clicking Calculate, you will see your monthly payment amount, total amount paid over the life of the loan, and total interest charged. The interactive chart shows your remaining balance over time, and the full amortization schedule table breaks down every single payment.

Step 4 Compare Scenarios

Use the Compare Scenarios tab to evaluate two different loan options side by side. This is especially useful when deciding between different loan terms or comparing offers from multiple lenders. You can see at a glance which option saves you more money in interest.

Understanding Amortization

Amortization is the process of spreading a loan into a series of fixed payments over time. Each payment is split between paying off interest and reducing the principal balance. In the early years of a loan, most of your payment goes toward interest. As time goes on, an increasing portion goes toward principal.

This is why making extra payments early in the loan term has such a significant impact. When you reduce the principal early, you reduce the amount of interest that accumulates on every subsequent payment, creating a compounding savings effect.

Amortization Formula Explained

The standard amortization formula for calculating monthly payments is:

M = P * [r(1+r)^n] / [(1+r)^n - 1]

Where M is the monthly payment, P is the loan principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments. This formula ensures that each payment is the same amount, while the split between principal and interest changes over time.

Tips for Saving on Your Loan

• Make biweekly payments instead of monthly. This results in 26 half-payments per year (equivalent to 13 full payments), shaving years off your loan.
• Round up your payment to the nearest hundred dollars. The extra goes directly to principal.
• Put any windfalls like tax refunds or bonuses toward a lump sum extra payment.
• Refinance when rates drop significantly. Use the comparison tool to see if the savings justify closing costs.
• Avoid extending your loan term when refinancing, as this can increase total interest even at a lower rate.
• Check if your loan has prepayment penalties before making extra payments.

Common Loan Types and Typical Terms

Mortgages are most commonly offered as 15-year or 30-year fixed rate loans. Adjustable rate mortgages (ARMs) may start with a lower rate but can change after an initial period. Car loans typically range from 36 to 72 months. Personal loans often run from 12 to 60 months. Student loans can have terms from 10 to 25 years depending on the repayment plan.

Each loan type has different considerations. For mortgages, you may also account for property taxes, insurance, and possibly private mortgage insurance (PMI) on top of the principal and interest calculated here. The amortization schedule from this tool focuses on the core loan repayment.

Examples and Impact

Consider a $300,000 mortgage at 6.5% for 30 years. The standard monthly payment is about $1,896. By adding just $200 per month in extra payments, you would save over $90,000 in interest and pay off the loan about 6 years early. A one-time extra payment of $10,000 in the first year saves roughly $30,000 in interest over the life of the loan.

Use the extra payment fields in the calculator above to model your specific situation. Even small additional amounts can make a meaningful difference over decades of repayment.

Frequently Asked Questions

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This amortization calculator tool was after analyzing search patterns, user requirements, and existing solutions. We tested across Chrome, Firefox, Safari, and Edge. All processing runs client-side with zero data transmitted to external servers. Last reviewed March 19, 2026.

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Amortization Explained

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What is an amortization calculator? ▼

An amortization calculator is a tool that breaks down each loan payment into principal and interest portions over the entire life of the loan, generating a complete schedule showing how your balance decreases over time. It helps borrowers understand exactly where their money goes each month and plan strategies for paying off loans faster.

How is the monthly payment calculated? ▼

The monthly payment is calculated using the standard amortization formula: M = P[r(1+r)^n]/[(1+r)^n-1], where P is the principal loan amount, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments. This produces a fixed payment that covers both principal and interest throughout the loan term.

What is the difference between principal and interest? ▼

Principal is the original amount borrowed that you are paying back. Interest is the cost charged by the lender for borrowing the money. Each monthly payment covers both: a portion reduces your principal balance, and the rest covers the interest charged on the remaining balance. Early in the loan, most of the payment is interest; later, most goes to principal.

How do extra payments affect my loan? ▼

Extra payments go directly toward reducing your principal balance. This means you pay less total interest over the life of the loan and can pay off the loan earlier than the original term. The earlier you make extra payments, the more you save, because you reduce the principal on which future interest is calculated.

What is a typical mortgage interest rate? ▼

Mortgage interest rates vary based on economic conditions, credit score, loan type, and term. Rates for a 30-year fixed mortgage have historically ranged from about 3% to 8%. Your specific rate will depend on your creditworthiness, down payment, and the lender. Always compare offers from multiple lenders to get the best rate.

Should I choose a 15-year or 30-year mortgage? ▼

A 15-year mortgage has higher monthly payments but significantly less total interest paid. A 30-year mortgage offers lower monthly payments, making it more affordable month-to-month, but costs considerably more in total interest. Use the Compare Scenarios tab to see exact differences for your loan amount and rates.

Can I use this calculator for car loans? ▼

Yes. This amortization calculator works for any fixed-rate installment loan, including car loans, personal loans, student loans, and mortgages. Simply enter the loan amount, annual interest rate, and loan term. The amortization schedule and payment breakdown work the same way regardless of loan type.

What does negative amortization mean? ▼

Negative amortization occurs when your monthly payment is not enough to cover the interest due, causing the unpaid interest to be added to the loan balance. This means you actually owe more over time instead of less. It can happen with certain adjustable-rate mortgages or payment-option loans. This calculator helps you understand proper amortization to avoid such situations.