VB6Parse / Library / Financial / fv

VB6 Library Reference

Fv Function Returns a Double specifying the future value of an annuity based on periodic, fixed payments and a fixed interest rate.

Syntax

Fv(rate, nper, pmt[, pv[, type]])

Parameters

Return Value

Returns a Double representing the future value of an annuity based on periodic, fixed payments and a fixed interest rate.

Remarks

Typical Uses

Basic Usage Examples

' Calculate future value of monthly savings
Dim monthlyDeposit As Double
Dim annualRate As Double
Dim years As Integer
Dim futureValue As Double
monthlyDeposit = -100  ' $100 per month (negative because it's paid out)
annualRate = 0.06      ' 6% annual interest
years = 10
' Calculate future value
futureValue = Fv(annualRate / 12, years * 12, monthlyDeposit)
' Returns approximately $16,387.93
' Calculate future value with initial deposit
Dim initialDeposit As Double
initialDeposit = -1000  ' $1000 initial deposit
futureValue = Fv(annualRate / 12, years * 12, monthlyDeposit, initialDeposit)
' Returns approximately $18,193.97
' Calculate with payments at beginning of period
futureValue = Fv(annualRate / 12, years * 12, monthlyDeposit, initialDeposit, 1)
' Returns approximately $18,284.68
' Calculate investment growth with no regular payments
Dim lumpSum As Double
lumpSum = -5000  ' $5000 one-time investment
futureValue = Fv(0.08 / 12, 5 * 12, 0, lumpSum)
' Returns approximately $7,449.23 (compound interest on lump sum)

Common Patterns

1. Monthly Savings Calculator

Function CalculateSavings(monthlyAmount As Double, years As Integer, _
                          annualRate As Double) As Double
    Dim monthlyRate As Double
    Dim periods As Integer
    monthlyRate = annualRate / 12
    periods = years * 12
    ' Negative because it's money paid out
    CalculateSavings = Fv(monthlyRate, periods, -monthlyAmount)
End Function
' Usage
Dim savings As Double
savings = CalculateSavings(200, 20, 0.07)  ' $200/month, 20 years, 7%
MsgBox "Future value: " & FormatCurrency(savings)

2. Retirement Planning

Function CalculateRetirementFund(monthlyContribution As Double, _
                                 currentAge As Integer, _
                                 retirementAge As Integer, _
                                 currentBalance As Double, _
                                 expectedReturn As Double) As Double
    Dim years As Integer
    Dim periods As Integer
    Dim monthlyRate As Double
    years = retirementAge - currentAge
    periods = years * 12
    monthlyRate = expectedReturn / 12
    CalculateRetirementFund = Fv(monthlyRate, periods, _
                                 -monthlyContribution, _
                                 -currentBalance)
End Function
' Usage
Dim retirementValue As Double
retirementValue = CalculateRetirementFund(500, 30, 65, 10000, 0.08)
Debug.Print "Retirement fund at 65: " & FormatCurrency(retirementValue)

3. College Savings Plan

Function CollegeSavingsPlan(yearsUntilCollege As Integer, _
                            monthlyDeposit As Double, _
                            initialAmount As Double, _
                            expectedRate As Double) As Double
    Dim monthlyRate As Double
    Dim periods As Integer
    monthlyRate = expectedRate / 12
    periods = yearsUntilCollege * 12
    CollegeSavingsPlan = Fv(monthlyRate, periods, _
                            -monthlyDeposit, _
                            -initialAmount)
End Function
' Usage
Dim collegeFund As Double
collegeFund = CollegeSavingsPlan(18, 250, 5000, 0.06)
MsgBox "College fund in 18 years: " & FormatCurrency(collegeFund)

4. Investment Comparison

Sub CompareInvestments()
    Dim option1 As Double
    Dim option2 As Double
    Dim years As Integer
    years = 10
    ' Option 1: $100/month at 6%
    option1 = Fv(0.06 / 12, years * 12, -100)
    ' Option 2: $50/month at 8%
    option2 = Fv(0.08 / 12, years * 12, -50)
    Debug.Print "Option 1 (6%): " & FormatCurrency(option1)
    Debug.Print "Option 2 (8%): " & FormatCurrency(option2)
    If option1 > option2 Then
        Debug.Print "Option 1 is better"
    Else
        Debug.Print "Option 2 is better"
    End If
End Sub

5. Compound Interest Calculator

Function CompoundInterest(principal As Double, rate As Double, _
                         years As Integer, _
                         Optional compoundFrequency As Integer = 12) As Double
    Dim periods As Integer
    Dim periodRate As Double
    periods = years * compoundFrequency
    periodRate = rate / compoundFrequency
    ' No periodic payment, just compound the principal
    CompoundInterest = Fv(periodRate, periods, 0, -principal)
End Function
' Usage
Dim finalAmount As Double
finalAmount = CompoundInterest(10000, 0.05, 10, 12)  ' Monthly compounding
Debug.Print "Principal grows to: " & FormatCurrency(finalAmount)

6. Savings Goal Calculator

Function MonthlyDepositNeeded(targetAmount As Double, _
                              years As Integer, _
                              rate As Double, _
                              Optional startingBalance As Double = 0) As Double
    ' This is the inverse - given FV, find PMT
    ' Using trial and error or formula
    Dim monthlyRate As Double
    Dim periods As Integer
    monthlyRate = rate / 12
    periods = years * 12
    ' Use Pmt function instead for accurate calculation
    ' This example shows how Fv relates to the goal
    Dim testPayment As Double
    testPayment = 100
    Do While Fv(monthlyRate, periods, -testPayment, -startingBalance) < targetAmount
        testPayment = testPayment + 10
    Loop
    MonthlyDepositNeeded = testPayment
End Function

7. Annuity Future Value

Function AnnuityFutureValue(payment As Double, rate As Double, _
                            years As Integer, _
                            paymentTiming As Integer) As Double
    ' paymentTiming: 0 = end of period, 1 = beginning of period
    Dim periods As Integer
    periods = years
    AnnuityFutureValue = Fv(rate, periods, -payment, 0, paymentTiming)
End Function
' Usage
Dim fvOrdinary As Double
Dim fvDue As Double
fvOrdinary = AnnuityFutureValue(1000, 0.05, 10, 0)  ' Ordinary annuity
fvDue = AnnuityFutureValue(1000, 0.05, 10, 1)       ' Annuity due
Debug.Print "Ordinary annuity FV: " & FormatCurrency(fvOrdinary)
Debug.Print "Annuity due FV: " & FormatCurrency(fvDue)

8. Investment Portfolio Projection

Type PortfolioProjection
    Years As Integer
    FutureValue As Double
End Type
Function ProjectPortfolio(monthlyDeposit As Double, _
                         startingBalance As Double, _
                         rate As Double, _
                         maxYears As Integer) As PortfolioProjection()
    Dim projections() As PortfolioProjection
    Dim i As Integer
    Dim monthlyRate As Double
    ReDim projections(1 To maxYears)
    monthlyRate = rate / 12
    For i = 1 To maxYears
        projections(i).Years = i
        projections(i).FutureValue = Fv(monthlyRate, i * 12, _
                                        -monthlyDeposit, _
                                        -startingBalance)
    Next i
    ProjectPortfolio = projections
End Function

9. Loan Payoff Calculator (Inverse Use)

Sub AnalyzeLoanPayoff()
    Dim loanAmount As Double
    Dim monthlyPayment As Double
    Dim annualRate As Double
    Dim years As Integer
    Dim remainingBalance As Double
    loanAmount = 200000     ' Initial loan
    monthlyPayment = 1200   ' Monthly payment
    annualRate = 0.045      ' 4.5% APR
    years = 5               ' After 5 years
    ' Future value will be negative (debt remaining)
    remainingBalance = -Fv(annualRate / 12, years * 12, _
                          monthlyPayment, -loanAmount)
    Debug.Print "Remaining balance after " & years & " years: " & _
                FormatCurrency(remainingBalance)
End Sub

10. Recurring Deposit Calculator

Sub RecurringDepositCalculator()
    Dim deposit As Double
    Dim rate As Double
    Dim quarters As Integer
    Dim maturityValue As Double
    deposit = 500           ' Quarterly deposit
    rate = 0.06 / 4        ' Quarterly rate (6% annual)
    quarters = 20          ' 5 years
    maturityValue = Fv(rate, quarters, -deposit)
    Debug.Print "Maturity value: " & FormatCurrency(maturityValue)
    Debug.Print "Total deposits: " & FormatCurrency(deposit * quarters)
    Debug.Print "Interest earned: " & _
                FormatCurrency(maturityValue - (deposit * quarters))
End Sub

Advanced Usage

1. Flexible Savings Calculator with UI

Sub CalculateAndDisplay()
    Dim monthlyDeposit As Double
    Dim years As Integer
    Dim annualRate As Double
    Dim initialBalance As Double
    Dim paymentType As Integer
    Dim futureValue As Double
    ' Get inputs from form controls
    monthlyDeposit = CDbl(txtMonthlyDeposit.Text)
    years = CInt(txtYears.Text)
    annualRate = CDbl(txtRate.Text) / 100
    initialBalance = CDbl(txtInitialBalance.Text)
    ' Check if payments at beginning or end
    paymentType = IIf(chkBeginning.Value = 1, 1, 0)
    ' Calculate
    futureValue = Fv(annualRate / 12, years * 12, _
                    -monthlyDeposit, _
                    -initialBalance, _
                    paymentType)
    ' Display result
    lblResult.Caption = "Future Value: " & FormatCurrency(futureValue, 2)
    ' Calculate total contributions
    Dim totalContributions As Double
    totalContributions = initialBalance + (monthlyDeposit * years * 12)
    ' Calculate interest earned
    Dim interestEarned As Double
    interestEarned = futureValue - totalContributions
    lblTotalDeposits.Caption = "Total Deposits: " & _
                               FormatCurrency(totalContributions, 2)
    lblInterest.Caption = "Interest Earned: " & _
                         FormatCurrency(interestEarned, 2)
End Sub

2. Scenario Analysis

Sub AnalyzeScenarios()
    Dim rates() As Double
    Dim deposit As Double
    Dim years As Integer
    Dim i As Integer
    deposit = 300
    years = 15
    rates = Array(0.04, 0.06, 0.08, 0.10)  ' Different return scenarios
    Debug.Print "Scenario Analysis for $" & deposit & "/month over " & years & " years:"
    Debug.Print String(60, "=")
    For i = LBound(rates) To UBound(rates)
        Dim fv As Double
        fv = Fv(rates(i) / 12, years * 12, -deposit)
        Debug.Print "At " & FormatPercent(rates(i), 0) & ": " & _
                   FormatCurrency(fv, 2) & " (gain: " & _
                   FormatCurrency(fv - (deposit * years * 12), 2) & ")"
    Next i
End Sub

3. Goal-Based Planning

Function YearsToReachGoal(targetAmount As Double, _
                          monthlyDeposit As Double, _
                          startingBalance As Double, _
                          annualRate As Double) As Double
    Dim years As Double
    Dim fv As Double
    Dim monthlyRate As Double
    monthlyRate = annualRate / 12
    years = 1
    Do While years <= 50  ' Max 50 years
        fv = Fv(monthlyRate, years * 12, -monthlyDeposit, -startingBalance)
        If fv >= targetAmount Then
            YearsToReachGoal = years
            Exit Function
        End If
        years = years + 0.25  ' Check quarterly
    Loop
    YearsToReachGoal = -1  ' Goal not reachable
End Function
' Usage
Dim yearsNeeded As Double
yearsNeeded = YearsToReachGoal(500000, 1000, 50000, 0.07)
If yearsNeeded > 0 Then
    MsgBox "You will reach your goal in " & Format(yearsNeeded, "0.0") & " years"
Else
    MsgBox "Goal not reachable with current parameters"
End If

4. Monte Carlo Simulation

Function SimulateFutureValue(deposit As Double, years As Integer, _
                             avgRate As Double, volatility As Double, _
                             simulations As Integer) As Variant
    Dim results() As Double
    Dim i As Integer
    Dim simulatedRate As Double
    ReDim results(1 To simulations)
    Randomize
    For i = 1 To simulations
        ' Simple random variation around average rate
        simulatedRate = avgRate + ((Rnd() - 0.5) * 2 * volatility)
        ' Ensure rate doesn't go negative
        If simulatedRate < 0 Then simulatedRate = 0
        results(i) = Fv(simulatedRate / 12, years * 12, -deposit)
    Next i
    SimulateFutureValue = results
End Function
' Analyze results
Sub AnalyzeSimulation()
    Dim results As Variant
    Dim avg As Double, minVal As Double, maxVal As Double
    Dim i As Integer
    results = SimulateFutureValue(500, 20, 0.07, 0.02, 1000)
    avg = 0
    minVal = 1E+308
    maxVal = -1E+308
    For i = 1 To UBound(results)
        avg = avg + results(i)
        If results(i) < minVal Then minVal = results(i)
        If results(i) > maxVal Then maxVal = results(i)
    Next i
    avg = avg / UBound(results)
    Debug.Print "Average FV: " & FormatCurrency(avg, 2)
    Debug.Print "Min FV: " & FormatCurrency(minVal, 2)
    Debug.Print "Max FV: " & FormatCurrency(maxVal, 2)
End Sub

5. Tax-Advantaged Account Calculator

Function TaxAdvantaged401k(salary As Double, contributionPct As Double, _
                           employerMatch As Double, years As Integer, _
                           currentBalance As Double, rate As Double) As Double
    Dim monthlyContribution As Double
    Dim monthlyEmployerMatch As Double
    Dim totalMonthlyDeposit As Double
    ' Calculate monthly contributions
    monthlyContribution = (salary * contributionPct) / 12
    monthlyEmployerMatch = (salary * employerMatch) / 12
    totalMonthlyDeposit = monthlyContribution + monthlyEmployerMatch
    TaxAdvantaged401k = Fv(rate / 12, years * 12, _
                           -totalMonthlyDeposit, _
                           -currentBalance)
End Function
' Usage
Dim retirement401k As Double
retirement401k = TaxAdvantaged401k(75000, 0.06, 0.03, 30, 25000, 0.08)
Debug.Print "401(k) at retirement: " & FormatCurrency(retirement401k, 2)

6. Education Savings with Increasing Contributions

Function EducationSavingsWithIncrease(initialMonthly As Double, _
                                      annualIncrease As Double, _
                                      years As Integer, _
                                      rate As Double) As Double
    Dim yearlyFV As Double
    Dim currentMonthly As Double
    Dim i As Integer
    yearlyFV = 0
    currentMonthly = initialMonthly
    For i = 1 To years
        ' Calculate FV for this year's contributions
        Dim yearContribution As Double
        yearContribution = Fv(rate / 12, (years - i + 1) * 12, _
                             -currentMonthly)
        yearlyFV = yearlyFV + yearContribution
        ' Increase for next year
        currentMonthly = currentMonthly * (1 + annualIncrease)
    Next i
    EducationSavingsWithIncrease = yearlyFV
End Function

Error Handling

Function SafeFv(rate As Double, nper As Integer, pmt As Double, _
                Optional pv As Variant, Optional pType As Variant) As Variant
    On Error GoTo ErrorHandler
    ' Validate inputs
    If nper <= 0 Then
        SafeFv = "Error: Number of periods must be positive"
        Exit Function
    End If
    If rate <= -1 Then
        SafeFv = "Error: Rate must be greater than -100%"
        Exit Function
    End If
    ' Set defaults
    If IsMissing(pv) Then pv = 0
    If IsMissing(pType) Then pType = 0
    ' Calculate
    SafeFv = Fv(rate, nper, pmt, pv, pType)
    Exit Function
ErrorHandler:
    Select Case Err.Number
        Case 5  ' Invalid procedure call
            SafeFv = "Error: Invalid arguments"
        Case 6  ' Overflow
            SafeFv = "Error: Result too large"
        Case 13  ' Type mismatch
            SafeFv = "Error: Invalid data types"
        Case Else
            SafeFv = "Error: " & Err.Description
    End Select
End Function

Common errors: - Error 5 (Invalid procedure call): Invalid argument values (e.g., negative periods). - Error 6 (Overflow): Result is too large to fit in a Double. - Error 13 (Type mismatch): Arguments are not numeric.

Performance Considerations

Best Practices

  1. Use negative values for cash outflows (payments, deposits)
  2. Use positive values for cash inflows (receipts, withdrawals)
  3. Match time units - if rate is monthly, nper should be in months
  4. Validate inputs - check for reasonable ranges
  5. Handle edge cases - zero rate, very long periods
  6. Document assumptions - especially for rate projections
  7. Consider inflation - future value in today's dollars may differ

Comparison with Other Functions

Fv vs Pv

' Fv: Future value of an investment
futureValue = Fv(0.06 / 12, 10 * 12, -100)  ' What will I have?
' Pv: Present value of an investment
presentValue = Pv(0.06 / 12, 10 * 12, -100)  ' What is it worth today?

Fv vs NPer

' Fv: Calculate future value given payments
fv = Fv(0.05 / 12, 120, -100)
' NPer: Calculate periods needed to reach a goal
periods = NPer(0.05 / 12, -100, 0, 16000)  ' How long to reach $16,000?

Fv vs Pmt

' Fv: Calculate future value given payment amount
fv = Fv(0.06 / 12, 120, -200)
' Pmt: Calculate payment needed to reach future value
payment = Pmt(0.06 / 12, 120, 0, -30000)  ' How much to save for $30,000?

Limitations

Mathematical Formula

The future value calculation uses the formula:

For type = 0 (payments at end of period):
FV = -PV * (1 + rate)^nper - PMT * [((1 + rate)^nper - 1) / rate]
For type = 1 (payments at beginning of period):
FV = -PV * (1 + rate)^nper - PMT * [((1 + rate)^nper - 1) / rate] * (1 + rate)
Special case when rate = 0:
FV = -PV - PMT * nper

Related Functions

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