See screen shot 1.

Formulas that do not appear in the figure:

• The formula in cell C17 is =LOAN (LOAN is the name of cell C4).
• The formula in cell C18 is =G17; copy the formula from cell C18 to all the cells in column C, starting from C18.

Amortization schedule with a grace period

• The difference between a regular amortization schedule and one with a grace period is that in the latter, the repayment of the principal is delayed. The loan agreement stipulates the month in which the repayment of principal begins. The interest on the loan is calculated, and the first interest payment starts with the first month after the month that the loan was accepted.
• See screen shot 2. Note that the formulas used are not PPMT and IPMT; these formulas are not appropriate when the calculations are not linear.

Amortization schedule for random payment

• See the formulas in screen shot 3 for calculating the sum of the principal and interest in every payment.
• The dates of the loan repayment are random. The interest is calculated according to the number of interest days divided by 365 days in a year.