Calculate the number of periods needed to reach a given value.

`PDURATION(rate, pv, fv)`

- rate - required argument for the rate of the investment
- pv - required argument for the present value of the investment
- fv - required argument for the future value of the investment

`=PDURATION(C5/C6,C7,C8)`

The PDURATION function can be used to calculate the number of periods it takes for an investment to reach a certain amount of money. For example, this will return 166.70 periods if the interest is compounded monthly.

The PDURATION function is a financial function that calculates the amount of periods required to reach a specified future value, based on a given rate and present value.

- The PDURATION function calculates the number of periods required for an initial investment to reach a given value.
- It returns a period length in units of time, such as months, years, or days.
- The function takes into account payment schedules, interest rates, and other factors to calculate the required duration.

The PDURATION function is a financial function used to calculate the number of periods required for an investment to reach a specified value.

The PDURATION function requires three non-negative values as arguments:

- Rate (the interest rate for the investment)
- PV (the present value of the investment)
- FV (the future value of the investment)

The purpose of the PDURATION function is to calculate the number of periods that are necessary for an investment to reach a specific value. This can be used to help plan investments and determine how long it will take to reach a certain goal.