VB6Parse / Library / Financial / pv

VB6 Library Reference

PV Function

Returns a Double specifying the present value of an annuity based on periodic, fixed payments to be paid in the future and a fixed interest rate.

Syntax

PV(rate, nper, pmt, [fv], [type])

Parameters

Return Value

Returns a Double specifying the present value of an annuity. The present value is the current value of a series of future payments or the current value of a future lump sum.

Remarks

The PV function is the inverse of the FV function. While FV calculates what a series of payments will be worth in the future, PV calculates what those same future payments are worth today, discounted by a rate of return.

An annuity is a series of fixed cash payments made over a period of time. An annuity can be a loan (such as a home mortgage) or an investment (such as a monthly savings plan).

The rate and nper arguments must be calculated using payment periods expressed in the same units. For example, if rate is calculated using months, nper must also be calculated using months.

For all arguments, cash paid out (such as deposits to savings) is represented by negative numbers; cash received (such as dividend checks) is represented by positive numbers.

Important Uses: - Loan Affordability: Calculate how much you can borrow given a specific payment amount - Investment Valuation: Determine current value of future cash flows - Annuity Pricing: Calculate lump sum value of periodic payments - Lease Analysis: Determine present value of lease payments

Typical Uses

  1. Loan Affordability: Calculate maximum loan amount based on affordable payment
  2. Investment Valuation: Determine present value of future investment returns
  3. Annuity Valuation: Calculate lump sum value of annuity payments
  4. Bond Pricing: Value bonds based on coupon payments and face value
  5. Lease vs Buy Analysis: Compare present value of lease payments to purchase price
  6. Pension Valuation: Calculate current value of future pension payments
  7. Structured Settlement: Determine lump sum value of periodic payments
  8. Capital Budgeting: Evaluate present value of project cash flows

Basic Examples

Example 1: Loan Affordability

' How much can you borrow if you can afford $500/month for 5 years at 6% APR?
Dim loanAmount As Double
loanAmount = Abs(PV(0.06 / 12, 5 * 12, -500))
' Returns approximately $25,775 (negative payment = money you pay out)

Example 2: Investment Present Value

' What's the present value of receiving $1,000/month for 10 years at 5% return?
Dim presentValue As Double
presentValue = Abs(PV(0.05 / 12, 10 * 12, 1000))
' Returns approximately $94,289 (positive payment = money you receive)

Example 3: Annuity Valuation

' Value of annuity paying $2,000/month for 20 years at 4% discount rate
Dim annuityValue As Double
annuityValue = Abs(PV(0.04 / 12, 20 * 12, 2000))
' Returns the lump sum equivalent value

Example 4: Lump Sum with Future Value

' Present value of $50,000 in 10 years at 6% annual return (no periodic payments)
Dim presentValue As Double
presentValue = Abs(PV(0.06, 10, 0, -50000))
' Returns approximately $27,920 (what you'd need to invest today)

Common Patterns

Pattern 1: CalculateAffordableLoan

Function CalculateAffordableLoan(monthlyPayment As Double, _
annualRate As Double, _
years As Integer) As Double
Dim monthlyRate As Double
Dim numPayments As Integer

monthlyRate = annualRate / 12
numPayments = years * 12

' Negative payment because it's money flowing out
CalculateAffordableLoan = Abs(PV(monthlyRate, numPayments, -monthlyPayment))
End Function

Pattern 2: ComparePaymentOptions

Function ComparePaymentOptions(payment1 As Double, years1 As Integer, _
payment2 As Double, years2 As Integer, _
rate As Double) As String
Dim pv1 As Double
Dim pv2 As Double

pv1 = Abs(PV(rate / 12, years1 * 12, -payment1))
pv2 = Abs(PV(rate / 12, years2 * 12, -payment2))

If pv1 > pv2 Then
ComparePaymentOptions = "Option 1 allows borrowing $" & _
Format(pv1 - pv2, "#,##0") & " more"
Else
ComparePaymentOptions = "Option 2 allows borrowing $" & _
Format(pv2 - pv1, "#,##0") & " more"
End If
End Function

Pattern 3: CalculateLumpSumEquivalent

Function CalculateLumpSumEquivalent(monthlyPayment As Double, _
years As Integer, _
discountRate As Double) As Double
' Calculate what a stream of payments is worth as a lump sum today
Dim monthlyRate As Double

monthlyRate = discountRate / 12
CalculateLumpSumEquivalent = Abs(PV(monthlyRate, years * 12, monthlyPayment))
End Function

Pattern 4: ValidatePVParameters

Function ValidatePVParameters(rate As Double, nper As Integer, _
pmt As Double) As Boolean
ValidatePVParameters = False

If nper <= 0 Then
MsgBox "Number of periods must be positive"
Exit Function
End If

If rate < -1 Then
MsgBox "Interest rate cannot be less than -100%"
Exit Function
End If

ValidatePVParameters = True
End Function

Pattern 5: CalculateBreakEvenLoanAmount

Function CalculateBreakEvenLoanAmount(payment As Double, _
rate As Double, _
years As Integer, _
upfrontCosts As Double) As Double
' Calculate loan amount where total cost equals upfront costs
Dim loanPV As Double

loanPV = Abs(PV(rate / 12, years * 12, -payment))
CalculateBreakEvenLoanAmount = loanPV - upfrontCosts
End Function

Pattern 6: PVOfMixedCashFlows

Function PVOfMixedCashFlows(regularPayment As Double, _
rate As Double, _
nper As Integer, _
futureValue As Double) As Double
' Calculate PV when you have both regular payments and a lump sum
PVOfMixedCashFlows = Abs(PV(rate, nper, regularPayment, futureValue))
End Function

Pattern 7: CalculateRequiredDownPayment

Function CalculateRequiredDownPayment(homePrice As Double, _
monthlyPayment As Double, _
rate As Double, _
years As Integer) As Double
Dim maxLoan As Double

maxLoan = Abs(PV(rate / 12, years * 12, -monthlyPayment))

If maxLoan >= homePrice Then
CalculateRequiredDownPayment = 0
Else
CalculateRequiredDownPayment = homePrice - maxLoan
End If
End Function

Pattern 8: CompareLumpSumVsAnnuity

Function CompareLumpSumVsAnnuity(lumpSum As Double, _
annuityPayment As Double, _
years As Integer, _
discountRate As Double) As String
Dim annuityPV As Double
Dim difference As Double

annuityPV = Abs(PV(discountRate / 12, years * 12, annuityPayment))
difference = lumpSum - annuityPV

If difference > 0 Then
CompareLumpSumVsAnnuity = "Lump sum is better by $" & Format(difference, "#,##0")
ElseIf difference < 0 Then
CompareLumpSumVsAnnuity = "Annuity is better by $" & Format(Abs(difference), "#,##0")
Else
CompareLumpSumVsAnnuity = "Both options are equal"
End If
End Function

Pattern 9: CalculateLeaseValue

Function CalculateLeaseValue(monthlyLease As Double, _
leaseTermMonths As Integer, _
discountRate As Double) As Double
' Calculate present value of all lease payments
CalculateLeaseValue = Abs(PV(discountRate / 12, leaseTermMonths, -monthlyLease))
End Function

Pattern 10: FindAffordablePayment

Function FindAffordablePayment(desiredLoan As Double, _
rate As Double, _
nper As Integer) As Double
' Reverse calculation: find payment from desired loan amount
' This uses Pmt, but demonstrates PV relationship
FindAffordablePayment = Abs(Pmt(rate, nper, desiredLoan))
End Function

Advanced Usage

Example 1: Comprehensive Loan Calculator

' Calculate loan amounts based on payment affordability
Class LoanAffordabilityCalculator
Private m_monthlyIncome As Double
Private m_monthlyDebts As Double
Private m_annualRate As Double
Private m_loanYears As Integer
Private m_debtToIncomeRatio As Double

Public Sub Initialize(monthlyIncome As Double, monthlyDebts As Double, _
annualRate As Double, loanYears As Integer)
m_monthlyIncome = monthlyIncome
m_monthlyDebts = monthlyDebts
m_annualRate = annualRate
m_loanYears = loanYears
m_debtToIncomeRatio = 0.43  ' Standard 43% DTI ratio
End Sub

Public Function GetMaxMonthlyPayment() As Double
Dim maxTotalDebt As Double
Dim maxPayment As Double

maxTotalDebt = m_monthlyIncome * m_debtToIncomeRatio
maxPayment = maxTotalDebt - m_monthlyDebts

If maxPayment < 0 Then maxPayment = 0
GetMaxMonthlyPayment = maxPayment
End Function

Public Function GetMaxLoanAmount() As Double
Dim maxPayment As Double
Dim monthlyRate As Double
Dim numPayments As Integer

maxPayment = GetMaxMonthlyPayment()
monthlyRate = m_annualRate / 12
numPayments = m_loanYears * 12

' Use PV to find how much can be borrowed
GetMaxLoanAmount = Abs(PV(monthlyRate, numPayments, -maxPayment))
End Function

Public Function GetLoanWithDownPayment(downPayment As Double) As Double
GetLoanWithDownPayment = GetMaxLoanAmount() + downPayment
End Function

Public Function GetRequiredDownPayment(homePrice As Double) As Double
Dim maxLoan As Double

maxLoan = GetMaxLoanAmount()

If maxLoan >= homePrice Then
GetRequiredDownPayment = 0
Else
GetRequiredDownPayment = homePrice - maxLoan
End If
End Function

Public Function GenerateAffordabilityReport() As String
Dim report As String
Dim maxPayment As Double
Dim maxLoan As Double

maxPayment = GetMaxMonthlyPayment()
maxLoan = GetMaxLoanAmount()

report = "Loan Affordability Analysis" & vbCrLf
report = report & String(50, "=") & vbCrLf
report = report & "Monthly Income: $" & Format(m_monthlyIncome, "#,##0") & vbCrLf
report = report & "Existing Debts: $" & Format(m_monthlyDebts, "#,##0") & vbCrLf
report = report & "DTI Ratio: " & Format(m_debtToIncomeRatio * 100, "0") & "%" & vbCrLf
report = report & String(50, "-") & vbCrLf
report = report & "Max Monthly Payment: $" & Format(maxPayment, "#,##0") & vbCrLf
report = report & "Interest Rate: " & Format(m_annualRate * 100, "0.00") & "%" & vbCrLf
report = report & "Loan Term: " & m_loanYears & " years" & vbCrLf
report = report & String(50, "-") & vbCrLf
report = report & "Maximum Loan Amount: $" & Format(maxLoan, "#,##0")

GenerateAffordabilityReport = report
End Function
End Class

Example 2: Annuity Comparison Tool

' Compare different annuity and lump sum options
Module AnnuityComparison
Private Type AnnuityOption
Name As String
Payment As Double
Years As Integer
IsLumpSum As Boolean
LumpSumAmount As Double
End Type

Public Function CompareOptions(options() As AnnuityOption, _
discountRate As Double) As String
Dim report As String
Dim i As Integer
Dim pv As Double
Dim monthlyRate As Double
Dim bestValue As Double
Dim bestIndex As Integer

monthlyRate = discountRate / 12
bestValue = 0
bestIndex = LBound(options)

report = "Annuity Option Comparison" & vbCrLf
report = report & "Discount Rate: " & Format(discountRate * 100, "0.0") & "%" & vbCrLf
report = report & String(60, "=") & vbCrLf
report = report & "Option              Type        Present Value" & vbCrLf
report = report & String(60, "-") & vbCrLf

For i = LBound(options) To UBound(options)
If options(i).IsLumpSum Then
pv = options(i).LumpSumAmount
Else
pv = Abs(PV(monthlyRate, options(i).Years * 12, options(i).Payment))
End If

If pv > bestValue Then
bestValue = pv
bestIndex = i
End If

report = report & Left(options(i).Name & Space(20), 20) & _
IIf(options(i).IsLumpSum, "Lump Sum    ", "Annuity     ") & _
"$" & Format(pv, "#,##0")

If i = bestIndex Then report = report & " *BEST*"
report = report & vbCrLf
Next i

report = report & String(60, "-") & vbCrLf
report = report & "Recommended: " & options(bestIndex).Name

CompareOptions = report
End Function

Public Function CalculateAnnuityYield(lumpSum As Double, _
monthlyPayment As Double, _
years As Integer) As Double
' Find the discount rate that makes PV equal to lump sum
' This is a simplified approximation
Dim rate As Double
Dim pv As Double
Dim diff As Double

rate = 0.05  ' Starting guess
Do
pv = Abs(PV(rate / 12, years * 12, monthlyPayment))
diff = pv - lumpSum

If Abs(diff) < 0.01 Then Exit Do

' Adjust rate
If diff > 0 Then
rate = rate + 0.0001
Else
rate = rate - 0.0001
End If
Loop While Abs(diff) > 0.01

CalculateAnnuityYield = rate
End Function
End Module

Example 3: Lease vs Buy Analyzer

' Compare leasing vs buying with present value analysis
Class LeaseVsBuyAnalyzer
Private m_purchasePrice As Double
Private m_monthlyLease As Double
Private m_leaseTermMonths As Integer
Private m_discountRate As Double
Private m_residualValue As Double

Public Sub Initialize(purchasePrice As Double, monthlyLease As Double, _
leaseTermMonths As Integer, discountRate As Double, _
residualValue As Double)
m_purchasePrice = purchasePrice
m_monthlyLease = monthlyLease
m_leaseTermMonths = leaseTermMonths
m_discountRate = discountRate
m_residualValue = residualValue
End Sub

Public Function GetLeasePresentValue() As Double
' Calculate PV of all lease payments
GetLeasePresentValue = Abs(PV(m_discountRate / 12, m_leaseTermMonths, -m_monthlyLease))
End Function

Public Function GetBuyPresentValue() As Double
' Calculate PV of buying (purchase price minus PV of residual value)
Dim pvResidual As Double

' PV of residual value (what it's worth after lease term)
pvResidual = Abs(PV(m_discountRate / 12, m_leaseTermMonths, 0, -m_residualValue))

GetBuyPresentValue = m_purchasePrice - pvResidual
End Function

Public Function GetRecommendation() As String
Dim leasePV As Double
Dim buyPV As Double
Dim difference As Double

leasePV = GetLeasePresentValue()
buyPV = GetBuyPresentValue()
difference = Abs(buyPV - leasePV)

If leasePV < buyPV Then
GetRecommendation = "LEASE - Saves $" & Format(difference, "#,##0") & " in PV"
ElseIf leasePV > buyPV Then
GetRecommendation = "BUY - Saves $" & Format(difference, "#,##0") & " in PV"
Else
GetRecommendation = "Either option - PV is equal"
End If
End Function

Public Function GenerateAnalysis() As String
Dim analysis As String
Dim leasePV As Double
Dim buyPV As Double

leasePV = GetLeasePresentValue()
buyPV = GetBuyPresentValue()

analysis = "Lease vs Buy Analysis" & vbCrLf
analysis = analysis & String(50, "=") & vbCrLf
analysis = analysis & "Purchase Price: $" & Format(m_purchasePrice, "#,##0") & vbCrLf
analysis = analysis & "Monthly Lease: $" & Format(m_monthlyLease, "#,##0") & vbCrLf
analysis = analysis & "Lease Term: " & m_leaseTermMonths & " months" & vbCrLf
analysis = analysis & "Discount Rate: " & Format(m_discountRate * 100, "0.0") & "%" & vbCrLf
analysis = analysis & "Residual Value: $" & Format(m_residualValue, "#,##0") & vbCrLf
analysis = analysis & String(50, "-") & vbCrLf
analysis = analysis & "Lease PV: $" & Format(leasePV, "#,##0") & vbCrLf
analysis = analysis & "Buy PV: $" & Format(buyPV, "#,##0") & vbCrLf
analysis = analysis & String(50, "-") & vbCrLf
analysis = analysis & "Recommendation: " & GetRecommendation()

GenerateAnalysis = analysis
End Function
End Class

Example 4: Pension Valuation Calculator

' Calculate present value of pension benefits
Class PensionValuator
Private m_monthlyPension As Double
Private m_yearsToRetirement As Integer
Private m_yearsOfPayments As Integer
Private m_discountRate As Double
Private m_inflationRate As Double

Public Sub SetPensionDetails(monthlyPension As Double, _
yearsToRetirement As Integer, _
yearsOfPayments As Integer)
m_monthlyPension = monthlyPension
m_yearsToRetirement = yearsToRetirement
m_yearsOfPayments = yearsOfPayments
End Sub

Public Sub SetEconomicAssumptions(discountRate As Double, inflationRate As Double)
m_discountRate = discountRate
m_inflationRate = inflationRate
End Sub

Public Function GetPensionPresentValue() As Double
Dim monthlyRate As Double
Dim numPayments As Integer
Dim pvAtRetirement As Double
Dim pvToday As Double

monthlyRate = m_discountRate / 12
numPayments = m_yearsOfPayments * 12

' Calculate PV at retirement
pvAtRetirement = Abs(PV(monthlyRate, numPayments, m_monthlyPension))

' Discount back to today
pvToday = Abs(PV(m_discountRate, m_yearsToRetirement, 0, -pvAtRetirement))

GetPensionPresentValue = pvToday
End Function

Public Function GetInflationAdjustedValue() As Double
Dim realRate As Double
Dim monthlyRate As Double
Dim numPayments As Integer
Dim pvAtRetirement As Double
Dim pvToday As Double

' Fisher equation: (1 + nominal) = (1 + real)(1 + inflation)
realRate = ((1 + m_discountRate) / (1 + m_inflationRate)) - 1
monthlyRate = realRate / 12
numPayments = m_yearsOfPayments * 12

pvAtRetirement = Abs(PV(monthlyRate, numPayments, m_monthlyPension))
pvToday = Abs(PV(realRate, m_yearsToRetirement, 0, -pvAtRetirement))

GetInflationAdjustedValue = pvToday
End Function

Public Function GenerateValuationReport() As String
Dim report As String
Dim nominalPV As Double
Dim realPV As Double
Dim totalPayments As Double

nominalPV = GetPensionPresentValue()
realPV = GetInflationAdjustedValue()
totalPayments = m_monthlyPension * m_yearsOfPayments * 12

report = "Pension Valuation Report" & vbCrLf
report = report & String(50, "=") & vbCrLf
report = report & "Monthly Pension: $" & Format(m_monthlyPension, "#,##0") & vbCrLf
report = report & "Years to Retirement: " & m_yearsToRetirement & vbCrLf
report = report & "Years of Payments: " & m_yearsOfPayments & vbCrLf
report = report & "Discount Rate: " & Format(m_discountRate * 100, "0.0") & "%" & vbCrLf
report = report & "Inflation Rate: " & Format(m_inflationRate * 100, "0.0") & "%" & vbCrLf
report = report & String(50, "-") & vbCrLf
report = report & "Total Nominal Payments: $" & Format(totalPayments, "#,##0") & vbCrLf
report = report & "Present Value (Nominal): $" & Format(nominalPV, "#,##0") & vbCrLf
report = report & "Present Value (Real): $" & Format(realPV, "#,##0") & vbCrLf
report = report & String(50, "-") & vbCrLf
report = report & "Value Reduction from Inflation: $" & _
Format(nominalPV - realPV, "#,##0") & " (" & _
Format(((nominalPV - realPV) / nominalPV) * 100, "0.0") & "%)"

GenerateValuationReport = report
End Function
End Class

Error Handling

The PV function can raise errors in the following situations:

Always validate input parameters:

On Error Resume Next
presentValue = PV(rate, nper, pmt, fv, type)
If Err.Number <> 0 Then
MsgBox "Error calculating present value: " & Err.Description
Err.Clear
End If
On Error GoTo 0

Performance Considerations

Best Practices

  1. Convert Rates Properly: Always divide annual rates by 12 for monthly calculations
  2. Match Time Units: Ensure rate and nper use the same time period
  3. Use Absolute Value: Use Abs() to display positive values to users
  4. Validate Inputs: Check that nper > 0 and rate is reasonable
  5. Handle Sign Conventions: Remember negative = outflow, positive = inflow
  6. Round for Display: Use Format() for currency display
  7. Document Assumptions: Clearly state discount rates and time periods
  8. Consider Inflation: Use real rates for inflation-adjusted analysis
  9. Test Edge Cases: Verify behavior with 0% rate, very long terms
  10. Compare with Pmt: Understand the inverse relationship between PV and Pmt
Function Purpose Returns Use Case
PV Present value of annuity Double (current value) Loan affordability, investment valuation
FV Future value of annuity Double (future value) Investment growth, savings goals
Pmt Periodic payment Double (payment amount) Loan payments, inverse of PV
NPV Net present value Double (NPV) Project evaluation with irregular cash flows
NPer Number of periods Double (period count) Time to goal calculation
Rate Interest rate Double (rate per period) Finding effective rate

Platform and Version Notes

Limitations

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