Calculating Inflation, retirement and cost of living adjustments over 30 years

[Roel Schroeven]

rbt wrote:
> Is this mathematically correct?
> 
> 
> def inflation():
>      start = int(str.strip(raw_input("How much money do you need each 
> month at the start of retirement: ")))
>      inflation = float(str.strip(raw_input("What will inflation average 
> over the next 30 years(.03, .04, etc): ")))
> 
>      for x in xrange(30):
>          start = start*inflation+start
>          print start
> 
> inflation()

I'm not really familiar with financial calculations, but it looks 
correct. There's a faster way though, since repeated multiplication is 
the same as taking the power with the number of years as the exponent:

def inflation():
     start = ... # same as before
     inflation = ... # same as before

     print start * (1+inflation)**30


-- 
If I have been able to see further, it was only because I stood
on the shoulders of giants.  -- Isaac Newton

Roel Schroeven