Calculate payments based on APR

[Robert T. Repko (R Squared Consultants)]

Believe it or not at 4/12/2009 11:20 PM, Kenneth Brody said:
>Robert T. Repko (R Squared Consultants) wrote:
>>Believe it or not at 4/12/2009 10:46 PM, Kenneth Brody said:
>>>Robert T. Repko (R Squared Consultants) wrote:
>>>>Does anyone have a routine that calculates monthly payments based 
>>>>on an APR.
>>>Would the TVM_PMT() function do what you're looking for?
>>I looked at that function but it gives me a different answer than 
>>the calculators I've used for finding payments based on an 
>>APR.  Before I started working on the program I used calculators on 
>>the Internet so I would know what answers I was supposed to get.  I 
>>used $1000.00, 13.9%, for 12 months, compounded monthly.  Using 
>>TVM_PMT() I get a monthly payment of 84.09, with a calculator I get 
>>89.74.  The description doesn't mention if it's simple or compound interest.
>
>Hmm...
>
>     xx(8,.2) = tvm_pmt("12","13.9"/"12","1000","0")
>
>gives me "-89.74", just like your calculator.
>
>What did you do that gave you a different number?
>
>--
>Kenneth Brody

I followed the example Laura had in her help file.
Interpreting the numbers in her example $200,000, 360 months (30 yr 
loan), at 7.25%

      if: ' What would be the payment for this loan?
    then: PMT = TVM_PMT("360",".0725","200000","0") ' PMT will be -631.40595650

I used:
eh=TVM_PMT("12",".139","1000","0")

I see my mistake, instead of using a monthly rate (.139/12) I used 
the APR of .139 in the calculations.

Thanks Ken I never would have seen my error.  I hate when I do that, 
spend days on a problem and the solution is right under my nose and I 
can't see it.