Calculate a loan amortization schedule row

Enter the original principal, nominal annual interest rate, full term in months, and the one-based payment number to inspect. The result separates that scheduled payment into interest and principal, then reports the balance remaining immediately after the payment. Zero-interest loans are supported, and an out-of-range payment number produces a clear input error.

Enter loan terms on a consistent monthly basis

Start with the original principal, meaning the amount financed before scheduled interest is added. Enter the annual interest rate as a percentage, so 6.5 means 6.5 percent rather than the decimal 0.065. Supply the complete term as a positive number of months and identify the payment using a one-based payment number: the first payment is 1, the twelfth is 12, and the final payment equals the term. The calculator assumes one payment per month, a fixed nominal annual rate, and equal scheduled payments over a fully amortizing term. It does not automatically include taxes, insurance, service charges, optional products, or additional principal payments. If a fee is financed as part of the opening balance, include it in principal; otherwise keep it separate. Use the contractual loan balance rather than a purchase price or asset value. The payment number must fall within the stated term. Asking for month 361 on a 360-month loan is invalid because no scheduled row exists after the loan’s contractual final payment.

Understand how the selected row is calculated

For a loan with interest, the annual percentage rate is divided by twelve and by one hundred to obtain the monthly decimal rate. The standard fixed-payment amortization formula determines the scheduled monthly payment. The calculator then derives the outstanding balance immediately before the requested payment without rounding through every earlier row. Interest for the selected row equals that opening balance multiplied by the monthly rate. Principal equals the scheduled payment minus that interest, and the remaining balance equals the opening balance minus the principal portion. This explains why early payments usually contain more interest while later payments direct more money toward principal, even though the scheduled payment stays constant. For an annual rate of exactly zero, the principal is divided evenly across the term, interest is zero, and the balance declines in equal steps. Monetary outputs are rounded to two decimal places for display. The underlying calculation retains full floating-point precision until the selected row is complete, avoiding cumulative cent-rounding drift from simulating a displayed schedule line by line.

Interpret the result and compare it with lender records

The response identifies the requested payment number and reports the scheduled payment, its interest component, its principal component, and the remaining balance immediately afterward. This makes a single-row result useful for checking a statement, estimating equity at a future installment, or feeding one period into a financial workflow without transferring a full schedule. Treat the figures as a standard mathematical estimate. A lender may round each prior row to cents, use daily interest, apply a different day-count convention, schedule payments on actual dates, or handle the final installment as a small adjustment. Extra payments, skipped payments, rate changes, fees, escrow charges, and late charges also change a real account but are outside this fixed-rate model. For those reasons, a lender’s statement can differ slightly even when the headline principal, annual rate, and term match. Keep all comparison inputs consistent and use the contractual statement for settlement decisions. The calculation is deterministic and needs no network access, so identical input always produces identical output. Browser use is available on this page, while an automated API request uses the published base price of $0.002.