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# math – Get rate in Excel without using "RATE" command

Questions:

I have less knowledge in Excel , now I want your help to calculate rate of interest in excel without using RATE command. (so that I can try to convert the formula in php)
This is the code we use in Excel

• B5= 60
• B4= 16070
• B3= 750000
• B6= 1

=RATE(B5,B4,-B3,0,B6)*12

It should give a result of “10.75%” as rate.

How can I get the same result without using ‘RATE’ or any other commands?

``````Function MyRATE(nper As Integer, pmt As Double, pv As Double, Optional fv As Double = 0, _
Optional PaymentEnd As Integer = 0, Optional guess As Double = 0.1)
Dim a As Double, b As Double, c As Double ' coefficients of the equation
Dim R As Double, RTmp As Double, i As Integer

' Initialize coefficients and R
R = 1 + guess
a = (pmt * (1 - PaymentEnd) - pv) / (pv + pmt * PaymentEnd)
b = (fv - pmt * PaymentEnd) / (pv + pmt * PaymentEnd)
c = (-pmt * (1 - PaymentEnd) - fv) / (pv + pmt * PaymentEnd)

' Iterate
For i = 1 To 20
RTmp = R - (R ^ (nper + 1) + a * R ^ nper + b * R + c) / ((nper + 1) * R ^ nper + a * nper * R ^ (nper - 1) + b)
If Abs(RTmp - R) < 0.0000001 Then Exit For
R = RTmp
Next i

If i <= 20 Then
MyRATE = RTmp - 1
Else
MyRATE = "N/A" ' Must try another guess
End If
End Function
``````

Note:

This is not my code. I have not tested it over a full range of inputs.

EDIT#1:

This is a User Defined Function. User Defined Functions (UDFs) are very easy to install and use:

1. ALT-F11 brings up the VBE window
2. ALT-I
ALT-M opens a fresh module
3. paste the stuff in and close the VBE window

If you save the workbook, the UDF will be saved with it.
If you are using a version of Excel later then 2003, you must save
the file as .xlsm rather than .xlsx

To remove the UDF:

1. bring up the VBE window as above
2. clear the code out
3. close the VBE window

To use the UDF from Excel worksheet cell:

=myrate(B5,B4,-B3,0,B6)*12