periods

Type

Financial Function

Purpose

The periods function calculates how long a financial transaction requires to reach a future target value given the presentvalue, futurevalue, installment payment, and interest rate.

Syntax

periods( presentvalue, futurevalue, installment, rate)

Returns

A numeric value (the number of periods needed to reach the target futurevalue of the investment).

Usage

If the installment payment increases the value of the investment (e.g., an annuity), the installment is expressed as a positive amount. If the payment decreases the value of the investment (e.g., loan amortization), the installment is expressed as a negative amount.

The interest rate, installment payments, and time periods must be based on the same terms. To determine periods as a number of months, the rate is expressed as the annual rate / 12. To determine periods as a number of weeks, the rate is expressed as 7*annual rate / 365.

Examples

ceil( periods( 10000, 0, -150, 8 / 12) )

Returns: 89

This example calculates how many months it takes to repay a loan of $10,000 at 8% annual interest with monthly installment payments of $150. The ceil function rounds up the result to the next integer.

ceil( periods( 0, 10000, 250, 10 / 12) )

Returns: 35

This example calculates how many months it takes to accumulate $10,000 in savings, if you begin with no money in the account, make monthly deposits of $250, and earn 10% annual interest.

Note: DataEase financial functions are derived from the formula shown below. (The double asterisks (meaning "raise to the power") cannot be used in a script).

futurevalue = principal * ((1 + (rate/100)) ** periods) + (installment/(rate/100)) * (((1 + (rate/100)) ** periods) - 1)

When typing fractions like 8 / 12, DataEase requires that you type a space before and after the / division symbol.