leebarnard
asked on
Algorithm to mimic Excel PV (present value) function
I need to programatically calculate present value. Excel has the function PV(rate,nper,pmt,fv,type) that I need reproduce exactly in javascript (I would think it would basically be the same in any language). The parameters are :
rate: interest rate per period
nper: total # of payment periods
pmt: the payment made each period
fv: the future value, or a cash balance you want to attain after the last payment is made
type: indicate if payment is made at the beginning or end of the period
Has anyone ever had to produce this mathmatical calculation in a program that they can share the algorithm with me
If I ever needed an expert this is the time.
ASKER
I could not seem to get this equation to produce the exact same results as Excel did with the same data. I did some further searching and found this equation that seems to produce the same results as Excel (within a few pennies)
http://www.investopedia.com/articles/03/101503.asp
thanks anyway
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ASKER
you are exactly right
thank you very much for your help
Thanks for the grade
PV*((1+ rate)^NPER)+ PMT*(1+rate*type)*(((1+ rate)^NPER)-1)/rate+FV = 0
so rearranging to solve PV
PV = -1*(FV+ PMT*(1+rate*type)*(((1+ rate)^NPER)-1)/rate)/((1+ rate)^NPER)
Cheers
Dave