Loan Amortization Calculator

A loan amortization calculator shows your fixed monthly payment, how much interest you will pay, and how your balance declines over time. It helps you compare loan terms, test extra payments, and understand when a lower payment actually means a higher total borrowing cost.

A loan amortization calculator estimates how a fixed-rate loan is repaid from the first payment to the last. It uses the loan amount, annual percentage rate, and repayment term to calculate a scheduled monthly payment. Then it breaks that payment into interest and principal for each period so you can see how the balance changes over time. Early payments usually contain more interest because the unpaid balance is still large. As the balance falls, more of each payment starts reducing principal.

This matters because the monthly payment alone does not tell you the full cost of borrowing. Two loans can have similar payments but very different total interest depending on the APR and term length. A loan amortization calculator makes those trade-offs visible. It shows how long payoff will take, how much interest will be charged over the full schedule, and how much faster the debt can disappear if you add extra principal each month.

Borrowers use a loan amortization calculator for personal loans, auto loans, student loan comparisons, business equipment financing, and other installment debt. It is useful before borrowing, during refinancing analysis, and while building a payoff plan for existing debt. In real life, this type of schedule helps with budgeting, deciding between shorter and longer terms, and identifying whether prepayments are worth the added cash outflow. Instead of guessing, you can see the payment structure and make a more informed borrowing decision.

1. Enter the original loan amount you plan to borrow or still owe.
2. Input the APR so the calculator can convert the annual rate into a monthly rate.
3. Enter the loan term in months, such as 36, 48, 60, or 72.
4. Add an optional extra monthly payment if you want to test a faster payoff strategy.
5. Enter a start date if you want the tool to estimate the payoff month and year.
6. Click Calculate to view payment size, total interest, payoff timing, and the amortization schedule.

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

• M: fixed monthly payment.
• P: original loan principal.
• r: monthly interest rate, equal to APR divided by 12.
• n: total number of monthly payments.

Monthly Payment

This is the required scheduled payment for a standard fixed-rate loan. It is the baseline number borrowers use to judge affordability before adding any extra payment.

Total Interest

This is the total dollar cost of borrowing above the original principal. It helps you compare whether a lower payment comes with too much long-term interest.

Estimated Payoff Time

This shows how long the loan lasts under your selected payment strategy. Extra principal usually shortens this timeline and reduces interest cost.

Interest Savings

This compares the accelerated schedule against the standard schedule. It shows how much interest can be avoided by paying more than the minimum each month.

Remaining Balance

The amortization table shows the unpaid balance after each payment. This helps with budgeting, refinancing decisions, and knowing how quickly equity or debt reduction is building.

Assume a borrower takes a $25,000 loan at 7.5% APR for 60 months, adds an extra $100 per month, and starts repayment in April 2026. These inputs are enough to build a full amortization schedule.

First, convert 7.5% APR into a monthly rate by dividing by 12. Next, apply the amortization formula across 60 payments to get a standard monthly payment of about $501. With the extra $100 payment, the borrower pays about $601 per month. Because the additional amount goes to principal, the balance shrinks faster and less interest accrues in later months.

Final result: the loan pays off in about 50 months instead of 60, and total interest drops by roughly $1,000 compared with the standard schedule. The outcome shows why amortization matters. Small recurring prepayments can materially reduce both payoff time and total borrowing cost.