The Amortization Table equation calculates the individual cells of an Amortization payment schedule.  This equation calculates the interest and principal due for each month of a loan period.

INPUTS

This equation will take as an input:

• Original Loan Amount (P) - the initial principal of the loan; i.e., the amount financed
• Loan term (n) - input as years
• Interest Rate (i)
• extra payment - an extra amount applied at each monthly payment
• payment num - a payment number in the sequence of payments
• choice - a choice of output value reporting either interest, principal, combined interest and principal, or loan balance 

The equation will output the Interest or principal portions applied for that payment number in the amortization payment period.

Notes

An Amortization table Shows, for each payment period of a loan, the payment amount that is applied to Principal and  the amount paid as interest.

For a standard fixed rate mortgage,  this amortization schedule will show that more money is applied as interest to the earlier payments.  As the loan matures,  the portion of the payment each month applied to principal increases, and the amount paid as interest decreases.

This equation will generate an Amortization table, if you execute it for each month of the term, and it will return as a result the requested values for Interest or Principal for each requested payment period.

The equation will allow you to choose the Interest paid for that payment period,  the payment amount applied as Principal,  the Combined (total) payment for that period, or the Loan Balance after the specified payment.

You can also enter an additional monthly payment into the calculation.  The additional monthly payment amount will be applied each payment period to the Principal payment.  The extra amount can be left blank to see results for a Standard Fixed Rate Amortization.

See Also

• Personal Finance Calculator