PV Calculation:

[UnixPanix]

I'm sure this is quite simple but I can't seem to get it to work, or I am using the wrong function.

A 30 Year Loan at 6.000 Percent would = my monthly payment

Field 1 = Loan Amount, say 150,000
Field 2 = The monthly payment via the calculation

My horrible attempts v1.0 = PV( Loan Amount , 6.999 , 30 )

"Field 1 is (Loan Amount)"
"Field 2 is (Monthly)"

Any help would be much appreciated.....

Filemaker Pro Version 5.5 Windows

 

[marty1452]

PV is for calculation of the present value of a loan. The corresponding values you show makes it look like you need to calculate a payment, not present value. But here are the rules.

The interest rate on PV or PMT needs to match your term always. If you wanted to calculate a 30 year mortgage in which you made 360 monthly payments, you have to match the rate to the number payment. To do this you need to divide the yearly interest rate by the number of years payments. Say 8% is the rate and you want to make 12 payment per year, you would simply divide 8 by 12 which gives you .6666666667. If you were to make one payment annually, you would just use the 8%. The term also has to reflect the payment schedule you would like. If you enter 30, there is no way for any formula to figure you want anything but 30 payments. If you want to calculate a PV or PMT on a 30 year or 360 month mortgage you must make sure your term is input that way. This does not limit you to strange input of the information. You may input 8 and 30 and get the answer you want, but the formula has to translate the entry to usable information. Heres an example:

Fields needed:
Loan Amount
Term
Rate
Payment

PMT(Loan Amount, (Rate/100)/12, Case(Term > 41 , Term , Term * 12)

Loan Amount is simply brought in. The rate is divided by 100 to turn 8 into .08 which represents 8%. Divided by 12 converts this into a monthly rate. Next the term may be entered as 30 or 360. I'm assuming mortgage here, but the formula above says if the number entered is larger than 41, take the number as is. So if you enter 180 in to term, 180 is larger than 41, so it uses the 180. If you want to calculate a 15 year loan, that's perfect. Next if you enter 15, the formula says that is less than 41 so times this by 12 which also equals 180.

When you pull in the PV or the PMT formula, they give you the default order of input. The example you gave does not match the input requirements for PV:

PV ( payment , interest rate , periods )

Where payment is above, you would enter your payment field name and so on.

PMT ( principal , interest rate , term )
likewise the word principal is replaced with your loan amount field name.

I hope this helps. Wait til you get to APR's. I spent months on that one. Filemaker does not support APR.

Marty

 

[UnixPanix]

Thank you for the detailed information. This will be very handy.....I can imagine that APRs are going to be alot of fun *sigh*

Thanks again.

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