[Overview][Constants][Types][Classes][Procedures and functions][Index] | Reference for unit 'Math' (#rtl)

# NumberOfPeriods

Calculate the number of periods for an investment

## Declaration

Source position: math.pp line 617

`function NumberOfPeriods(`
`ARate: Float;`
`APayment: Float;`
`APresentValue: Float;`
`AFutureValue: Float;`
`APaymentTime: TPaymentTime`
`):Float;`

## Description

NumberOfPeriods calculates the number of periods (n) needed to obtain future value of an investment in the cash flow formula (see CashFlowFunctions). The function result is the number of periods a payment APayment (PMT) must be paid in order to obtain a future value AFutureValue for an investment of a start value APresentValue (PV), where APayment (PMT) is invested at a rate ARate (q).

The APaymentTime parameter determines whether the investment (payment) is an ordinary annuity or an annuity due: ptEndOfPeriod NumberOfPeriods must be used if payments are at the end of each period. If the payments are at the beginning of the periode, ptStartOfPeriod must be used.

## See also

FutureValue |  | Calculate the future value of an investment.
InterestRate |  | Calculate the interest rate value of an investment
Payment |  | Calculate the payment for an investment
PresentValue |  | Calculate the present value given the future value of an investment.
TPaymentTime |  | Type used in financial (interest) calculations.
CashFlowFunctions |  | Cash flow functions