PMT calculates the standard payment for a loan with fixed principal and interest payments, such as a standard mortgage. PPMT and IPMT calculate the specific principal and interest components of the total payment. Since the mix of principal and interest change over time, you must also specific the payment number when using PPMT and IPMT (e.g., 4^{th} payment on the loan).

**Example**: You are calculating the monthly payment on a loan. Use PMT to calculate the payment based on the loan’s interest rate, number of payments, and amount (pv or present value).

**Tip**: Make sure to match your PMT inputs to the loan’s terms. For example, if a loan is monthly and the interest rate is annual, divide the interest rate by 12 to convert it to a monthly rate. Similarly, if payments are made at the beginning of each month instead of the end, set type = 1. PMT returns a negative value for a positive pv argument so add a negative if you want your payment to return as a positive value.