Free Amortization Table by Month Calculator

This free amortization table by month calculator estimates a fixed-rate loan’s monthly payment, total interest, and payoff schedule from the loan amount, annual APR, and term. Enter those three figures to see the payment and understand how each monthly payment is divided between interest and principal.

Formula

The calculator uses the standard fixed-payment loan formula. It first finds the monthly payment, then estimates total interest by subtracting the amount borrowed from all scheduled payments.

• Monthly payment: M = P × r ÷ [1 − (1 + r)⁻ⁿ]
• Total interest: I = M × n − P
• Monthly rate: r = APR ÷ 1,200
• Number of payments: n = loan term in years × 12

P is the principal, or starting loan balance, in dollars; APR is the annual percentage rate entered as a percent; r is the monthly rate as a decimal; n is the number of monthly payments; M is the monthly payment in dollars; and I is total interest in dollars. For example, an 8% APR becomes 0.08 ÷ 12, or about 0.006667 per month. The calculator displays the payment to the nearest cent. Its total-interest output uses that displayed, cent-rounded payment multiplied by the number of months, less the original principal.

Worked Example

Using the defaults—$20,000 principal, 8% APR, and a five-year term—the schedule has 5 × 12 = 60 monthly payments. The monthly rate is 8 ÷ 1,200 = 0.0066667.

1. Substitute into the payment formula: M = 20,000 × 0.0066667 ÷ [1 − (1.0066667)⁻⁶⁰].
2. The unrounded payment is about $405.527; rounded to cents, the monthly payment is $405.53.
3. Total scheduled payments, using the rounded payment, are $405.53 × 60 = $24,331.80.
4. Total interest is $24,331.80 − $20,000 = $4,331.80.

Assumptions

• The interest rate stays fixed for the full term.
• Payments are made monthly at the end of each period, with the first payment one month after borrowing.
• Interest compounds monthly at APR divided by 12.
• The estimate does not include fees, taxes, insurance, PMI, escrow, or other charges.

How a Monthly Amortization Table Works

An amortization table lists each scheduled payment period and shows how the balance changes. A full table commonly includes the payment number or date, starting balance, payment, interest portion, principal portion, and ending balance. Early in a typical fixed-rate loan, the balance is relatively high, so more of the payment goes to interest. As principal is repaid, interest for later periods is calculated on a smaller balance, and more of the same payment goes toward principal.

For a month-by-month calculation, interest for a period is generally the opening balance multiplied by the monthly rate. The principal portion is the payment minus that period’s interest, and the closing balance is the opening balance minus principal repaid. For example, on a $20,000 balance at 8% APR, the first month’s estimated interest is $20,000 × 0.0066667, or about $133.33. With the example payment of $405.53, roughly $272.20 goes to principal, leaving about $19,727.80. Actual lender schedules can differ because of payment dates, daily-interest methods, rounding, or contract terms.

When to Use the Estimate and How to Read It

This calculator is useful for understanding the basic cost pattern of a fixed-rate loan, checking a quoted payment’s general arithmetic, or seeing how loan amount, APR, and term feed into payment and total interest. It is not a complete lender-generated amortization table: the outputs summarize the scheduled payment and interest rather than listing every month’s balance.

A lower monthly payment does not necessarily mean less interest over the life of a loan. Holding principal and APR constant, extending the term generally increases the number of payments, and therefore can increase total interest even when each payment is smaller. Conversely, a shorter term usually means fewer scheduled payments, but a higher monthly payment under the same assumptions. These are mathematical relationships, not a recommendation about which term to select.

To build or verify a detailed table, calculate each period’s interest from the opening balance, subtract that from the payment to find principal repaid, and update the balance. Repeat through the final period. Use the lender’s payment schedule when available, since its day-count convention and rounding rules may control the actual figures.

Common Sources of Differences

• APR versus monthly rate: Enter annual APR as a percentage, such as 8—not 0.08 or 8 per month. The formula converts it to a monthly rate by dividing by 1,200.
• Term units: Enter the term in years. The calculator multiplies years by 12; entering months as though they were years would greatly overstate the schedule length.
• Rounding: Lenders may round interest or payment components at each period. Repeated cent rounding can make a final balance or total differ slightly from a formula using unrounded values.
• Fees and add-ons: The calculation treats the entered loan amount as principal and omits fees and other costs unless they are included in that amount.
• Variable rates or irregular payments: The formula assumes a fixed APR and equal monthly payments. Rate changes, skipped or late payments, extra principal, and unusual payment dates require a different schedule.

Related Question: Does an Amortization Table Show the Exact Payoff?

Not necessarily. A standard schedule shows planned payments under stated assumptions. A payoff amount on a particular date may include interest accrued since the last payment and other contract-specific amounts, while the calculator does not model those items. Likewise, making an extra payment can change the remaining balance and later interest; it is not reflected in this estimate. Ask the lender or servicer for the applicable payoff figure and an updated schedule for exact account details.

Frequently Asked Questions

Can I get a free amortization table by month?
This calculator is free to use and estimates a fixed-rate monthly payment and total interest. It does not print a row for every month; a lender’s schedule or a spreadsheet can provide the period-by-period entries.

What information do I need to make a monthly amortization schedule?
You need the starting principal, annual interest rate, payment frequency, term, and payment timing. Fees, rate changes, extra payments, or a daily-interest method may also matter for a schedule that matches a specific loan.

Why does the interest portion decrease each month?
With a fixed rate and regular payments, interest is calculated on the remaining principal. As that balance falls, the interest due for a period generally falls too, leaving a larger share of the payment for principal.

Is APR the same as the monthly interest rate?
No. APR is entered here as an annual percentage. This estimate divides it by 12 to get a nominal monthly rate; APR may also reflect costs or calculation conventions that this simplified payment formula does not model separately.

Why might my lender’s payment or total differ?
The loan may include charges, use different rounding or payment-date rules, or calculate interest using a different method. Compare the inputs and assumptions, then use the lender’s disclosure for the contract figures.

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

Related

• Amortization Distribution Table: How to Read It
• 30 Year Amortization Table: Payment and Balance
• American Amortization Table Calculator and Guide

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 | $ | p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)) | 2
out int | Total interest | $ | pmt * yrs * 12 - p | 2