Software for HP15c

  • Weighted Average

    The weighted average uses the statistic registers and leaves avg(y) weighted by x in y, and avg(x) weighted by y in x:

    Lbl 0 -so that it coincides in the same key as avg(x)

    rcl 7

    rcl / 3

    rcl 7

    rcl / 5


    NPV and IRR

    The Net Present Value and IRR are a little longer. Requires 11 registers and is valid for up to 10 periods. Data is not destroyed and can be used with other interest rates. I take care of not using labels used by TVM!

    Net Present Value: It takes the following arguments:

    Number of periods: register .1

    Initial cashflow: register 0

    cashflows for periods 1 to 9: registers 1 to 9 (how clever ;-))

    discount rate in %: register x

    NPV result: register x


    LBL 1


    2 - from % to decimal




    1/x - calculate 1/(1+i)



    ENTER - to load the stack with 1/(1+i)

    RCL .1 - number of periods (so that is is kept for further trials with other interest rates)

    STO I


    LBL .2 - loop for periods

    RCL + (I)

    X - calculates f(n) = (f(n-1)+ I(n))/(1+i)

    DSE I

    GTO .2 - Return if not 0

    RCL + 0 - Add start cashflow


    IRR - this is the elegance of the HP-15 - just load your guesses in x and I and use SOLVE ( f SOLVE 1)