Free Amortization Table Calculator and Loan Schedule

Use this free amortization table calculator to estimate each monthly payment’s split between principal and interest, along with the remaining balance over time. Enter the loan amount, annual APR, and term to get the monthly payment and total interest; the schedule itself can be generated from those figures using the method explained below.

Formula

The calculator uses the standard fixed-payment amortizing-loan formula. It first calculates a level monthly payment, rounds that payment to cents, and then estimates total interest as all scheduled payments minus the original principal.

• P is the starting loan principal, in dollars.
• a is the annual percentage rate (APR), entered as a percentage per year.
• r is the monthly interest rate, calculated as a / 1200.
• y is the term in years, and n is the number of monthly payments, y × 12.
• M is the monthly payment, in dollars, rounded to the nearest cent.
• I is estimated total interest over the scheduled term, in dollars.

In symbols, M = round[P × r / (1 − (1 + r)⁻ⁿ), 2]. Then I = M × n − P. The table’s balance calculation can be written as B_k = P(1 + r)^k − M[((1 + r)^k − 1) / r], where k is the number of payments already made and B_k is the estimated balance afterward.

Worked Example

Using the calculator’s defaults: P = $20,000, APR = 8%, and y = 5 years.

1. Convert the annual APR to a monthly rate: r = 8 / 1200 = 0.0066667, or about 0.66667% per month.
2. Find the number of monthly payments: n = 5 × 12 = 60.
3. Apply the payment formula: M = round[$20,000 × 0.0066667 / (1 − (1.0066667)⁻⁶⁰), 2] = $405.53 per month.
4. Calculate total interest using the rounded payment: I = $405.53 × 60 − $20,000 = $4,331.80.

These results describe the fixed-payment estimate. They do not show every row of the schedule, but the monthly principal-and-interest allocation follows the same rate and balance calculation. Small differences can arise in a lender’s final payment because real accounts may round each period or apply payments on specific dates.

Assumptions

• The interest rate stays fixed for the entire term.
• Payments are made monthly, at the end of each monthly period.
• Interest is modelled with monthly compounding at APR / 12.
• Fees, taxes, insurance, mortgage insurance, escrow, late charges, and payment-date effects are not included.

What an Amortization Table Shows

An amortization table, also called an amortization schedule, lays out a loan period by period. A typical monthly row shows the payment, the amount applied to interest, the amount applied to principal, and the balance remaining after payment. The schedule makes visible a feature of level-payment loans that can be surprising: the payment may stay the same while its composition changes.

For each period, interest is generally calculated on the outstanding balance. In a simplified monthly model, interest for a row is the opening balance multiplied by the monthly rate. Principal paid is the scheduled payment minus that period’s interest. The next balance is the opening balance minus principal paid. Early in a loan, the balance is larger, so more of a level payment goes to interest. As the balance falls, the interest portion generally shrinks and more of the payment reduces principal.

How to Read the Schedule

Suppose a row begins with a balance of $10,000 and the monthly rate is 0.66667%. The estimated interest for that month is about $66.67. If the scheduled payment is $405.53, approximately $338.86 goes to principal, leaving about $9,661.14. Those are illustrative rounded figures; a real statement may differ because of exact posting dates and the lender’s rounding method.

Look at the balance column to understand what remains after each payment, not just the payment amount. The total-interest figure is the interest projected across the full schedule under the stated assumptions. It is not necessarily the interest that will appear on an actual account if payments change, the loan is paid off early, or the rate is variable.

When to Use a Free Amortization Table

A table is useful when a single monthly-payment figure does not answer the question. It can help you see how the balance changes over time, estimate the interest portion of a particular payment, or compare a schedule with the terms shown in a loan disclosure. It can also illustrate how changing the principal, APR, or term changes the arithmetic. Any comparison should use figures supplied for the specific loans being examined; this calculator does not provide market rates or lender terms.

For a detailed schedule, calculate each row in sequence: opening balance × monthly rate gives interest; payment minus interest gives principal; opening balance minus principal gives closing balance. The following period starts with that closing balance. Continue until the balance reaches zero, adjusting the final payment if necessary. Because cents are rounded, the last row may not match a schedule created with a lender’s exact accounting conventions.

Common Limits and Mistakes

• Entering APR as a decimal: Enter 8 for 8%, not 0.08. The calculator converts an annual percentage to a monthly rate by dividing by 1,200.
• Confusing term units: The term field is in years. A five-year term means 60 monthly payments, not five payments.
• Treating the estimate as a statement: This model does not know the lender’s payment dates, fees, rate changes, or rounding rules.
• Assuming every loan uses level payments: The formula applies to a fixed-rate loan with regular, equal monthly payments. Interest-only periods, balloon payments, variable rates, and irregular payment plans need a different model.
• Forgetting extra payments: Additional principal payments can change the balance path and future interest. They are not included here, and their treatment can depend on how the lender applies them.

A common misconception is that the interest portion of every payment is a fixed share of the original loan. In an amortizing schedule, it is usually based on the current balance, so the split shifts over time even when the scheduled payment does not. Also, APR and a nominal monthly rate are related inputs in this estimate, but the calculator does not model every cost that may be reflected in a loan’s disclosed APR.

Frequently Asked Questions

Is this amortization table calculator free?
Yes. The calculator estimates a monthly payment and total interest from the amount, APR, and term entered. The explanation also gives the row-by-row method for constructing a schedule.

Does an amortization table show the remaining balance?
A full schedule normally includes a balance after each payment. This calculator returns the payment and projected total interest; the balance at a particular month can be estimated with the balance formula above.

Why does more of an early payment go to interest?
Interest is calculated on the outstanding principal in this model. The balance is usually highest at the beginning, so the interest amount is larger then; as principal falls, the interest portion generally falls too.

Can I use this for a variable-rate loan?
Only as a fixed-rate snapshot for the APR entered. If the rate changes, the payment or schedule may change as well, so one fixed-rate calculation cannot reproduce the full variable-rate path.

Why does my lender’s schedule differ by a few cents?
Payment timing, daily-interest methods, rounding at each step, fees, and the final-payment adjustment can produce small differences. Check the lender’s disclosure or account schedule for the figures used on the loan.

This result is an estimate for educational purposes, and the lender’s disclosure gives the exact figures.

Related

• 15-Year Loan Amortization Table and Calculator
• Annual Loan Amortization Table: Formula and Example
• Amortization Table Example: Monthly Loan Breakdown

in p | Loan amount | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Loan term | years | 5 | 0.0833 | 50
out pmt | Monthly payment | $ | round(p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) | 2
out int | Total interest | $ | pmt * yrs * 12 - p | 2