# How To Convert a Fraction to a Decimal Number

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### Summary

This article provides a routine to convert a string that contains a fraction in the form "a," "a/b," or "a b/c" into a double precision floating-point number.

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Sometimes it is more convenient to input values as fractions instead of decimal numbers. The following routine converts a string containing a fraction to a decimal number:
1. Create a new Visual Basic for Applications project and add the following code to a module:

### Sample Code

``      Function Frac2Num(ByVal X As String) As Double      Dim P As Integer, N As Double, Num As Double, Den As Double         X = Trim\$(X)         P = InStr(X, "/")         If P = 0 Then            N = Val(X)         Else            Den = Val(Mid\$(X, P + 1))            If Den = 0 Then Error 11    ' Divide by zero            X = Trim\$(Left\$(X, P - 1))            P = InStr(X, " ")            If P = 0 Then               Num = Val(X)            Else               Num = Val(Mid\$(X, P + 1))               N = Val(Left\$(X, P - 1))            End If         End If         If Den <> 0 Then            N = N + Num / Den         End If         Frac2Num = N      End Function``
2. In the Debug/Immediate window, test:
? Frac2Num("5 3/4"), Frac2Num("2/8")
Result: 5.75 0.25
Note: Numbers in the input string do not have to be whole numbers. They can contain decimal values and negative numbers.