Interest and Payment Calculations
I am working on a worksheet that shows payment information for mortgages.
However, the results I get for the payment is off by just a little bit
(nothing consistent) and the APR is consistently wrong (always the same as
the interest rate).
Here is an example of what I have:
B6 - $139,000.00 (loan amount)
B7 - 240 (total number of payments)
B8 - 12 (number of payments per year)
B11 - 7.00% (interest rate)
B15 - 365/360 (Interest method)
F15 - $0.00 (Fees for the mortgage, if any)
To calculate the APR, I am using the following:
=RATE(B7,PMT(B11/12,B7,B6),B6-F15)*12
My results are 7% and it should be 7.126%. Every time I use this
calculation, the APR comes out the same as the Interest Rate.
Also, my monthly payment is incorrect. To calculate it, I am doing the
following:
1st - I am using the following number:
A38 - 0.0735439979799297
This number is calculated from the formula:
=IF(B15="365/365",1*(1+B11/365)^365-1,IF(B15="30/360",1*(1+B11/360)^30-1,IF(B15="365/360",1*(1+B11/360)^365-1,
IF(B15="30/365",1*(1+B11/365)^30-1,"")))). I was told on a previous post
that this is how I would work with the different interest types.
So, the monthly payment is calculated as
=IF(B15="365/365",PMT(A38/12,B39*12,-B6),IF(B15="365/360",PMT(A38/12,B39*12,-B6),IF(B15="30/360",PMT(A38,B39*12,-B6),IF(B15="30/365",PMT(A38,B39*12,-B6),""))))
B39 = 20 (number of years)
I am getting $1107.43 for the monthly payment, but it should be $1086.22.
Does anyone see what I am doing wrong? I have looked at this until I am
blue in the face and have no idea what to do.
Thank you in advance for your time.
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