What is an amortization schedule?

An amortization schedule is a complete table showing every payment over the life of a loan, broken down into principal and interest portions. It shows the remaining balance after each payment, how much interest you pay each period, and how much of your payment goes toward reducing the principal. Our calculator generates a full amortization schedule for any loan scenario, including extra payments.

How is loan interest calculated?

Loan interest for each payment period is calculated by multiplying the current outstanding loan balance by the periodic interest rate. The periodic rate is the annual percentage rate (APR) divided by the number of payment periods per year, adjusted for compounding frequency. For example, on a $300,000 loan at 6.5% APR with monthly payments, the first month's interest is $300,000 × (6.5% ÷ 12) = $1,625.

Why do early payments contain more interest?

Early payments contain more interest because the loan balance is at its highest at the beginning of the loan term. Interest is calculated on the outstanding balance, so a larger balance generates more interest. As the principal is gradually paid down, the interest portion of each payment decreases, and more of the fixed payment goes toward reducing the principal.

Can I pay off my mortgage early?

Yes, most mortgages allow early repayment without penalty. However, some loans have prepayment penalties, typically 1-3% of the outstanding balance if paid off within the first 3-5 years. Always check your loan agreement or ask your lender. Our calculator shows how extra payments accelerate your payoff and save interest.

Do extra payments reduce interest?

Yes, every extra dollar you pay toward principal reduces the balance that future interest is calculated on. This creates a compounding effect — paying $200 extra in the first month of a $300,000 loan at 6.5% saves approximately $1,200 in interest over the remaining 30 years. The earlier you make extra payments, the more interest you save.

How often should I make extra payments?

Monthly extra payments are the most effective because they reduce the principal balance sooner, giving you the maximum interest savings. However, any extra payment — whether monthly, one-time, or annual — saves interest. Switching to bi-weekly payments (half your monthly payment every two weeks) effectively makes one extra payment per year, which can save thousands in interest.

What happens if interest rates change?

For fixed-rate loans, the interest rate is locked for the entire loan term, so your payment never changes. For adjustable-rate mortgages (ARMs), the rate adjusts periodically based on market indices. Our calculator models fixed-rate amortization. For ARMs, you would need to recalculate after each adjustment period using the new rate.

Can I export the amortization schedule?

Yes, the amortization schedule generated by our calculator can be copied to your clipboard using the "Copy Results" button. You can paste it into a spreadsheet application like Excel or Google Sheets for further analysis, filtering, or printing.

Is this calculator accurate?

Yes, this calculator uses the standard amortization formula M = P × [r(1+r)^n] / [(1+r)^n − 1] and accurately computes the payment breakdown for any fixed-rate loan. It accounts for different payment frequencies, compounding frequencies, and extra payments. The results are suitable for mortgages, auto loans, personal loans, student loans, and business loans.

Does it work for auto loans?

Yes, simply enter your auto loan amount, interest rate, and loan term. Auto loans typically have shorter terms (3-7 years) and are fully amortizing, meaning they are paid off by the end of the term. Our calculator handles any loan amount, rate, and term combination.

What is the difference between simple interest and amortized interest?

Simple interest is calculated only on the original principal amount, while amortized interest is calculated on the declining balance. Most installment loans (mortgages, auto loans, personal loans) use amortized interest, where each payment covers the interest accrued since the last payment plus a portion of principal. This is why early payments are mostly interest — the balance is highest at the start.

How does payment frequency affect total interest?

More frequent payments reduce total interest because principal is paid down sooner, reducing the balance that interest accrues on. Bi-weekly payments (26 per year) are equivalent to 13 monthly payments per year (one extra payment annually), which can save thousands in interest and shorten the loan term by several years. Weekly payments save even more.

What is the effective interest rate?

The effective interest rate (also called the annual equivalent rate or APR) accounts for the effect of compounding frequency. It represents the true annual cost of borrowing. For example, a loan with a 6.5% nominal rate compounded monthly has an effective rate of approximately 6.70%. Our calculator displays both the nominal and effective rate.

How does compounding frequency affect my loan?

Compounding frequency determines how often interest is calculated and added to the loan balance. More frequent compounding (daily or monthly) results in slightly more total interest compared to less frequent compounding (quarterly or annually). Most mortgages use monthly compounding, while some personal loans may use daily or quarterly compounding. Our calculator accurately models any compounding frequency.

Can I compare two loan scenarios?

Yes, our calculator includes a built-in comparison mode that lets you compare two loan scenarios side by side. You can compare different loan amounts, interest rates, terms, and extra payment amounts. The comparison shows the difference in monthly payment, total interest, total cost, and payoff time.

Amortization Calculator

Free Amortization Calculator with interactive charts, payment schedule, extra payment analysis, and downloadable loan repayment tables. Compare scenarios and see how extra payments save interest.

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