
1. Re: How to do Compound interest calculations in FMP?
SteveMartino Apr 30, 2014 9:15 AM (in response to JudeAshton)You might want to look at some custom functions:
http://www.briandunning.com/filemakercustomfunctions/results.php

2. Re: How to do Compound interest calculations in FMP?
philmodjunk Apr 30, 2014 9:49 AM (in response to JudeAshton)If you can look up the actual algebra used to compute FV in Excel, we can show you how to set up an equivalent calculation in FileMakerwhich could be set up as a custom function, but if this works as I vaguely recall, it won't have to be a custom function.
There is an FV function in FileMaker: FV(payment; interestRate; periods)
How does it differ from the Excel version?

3. Re: How to do Compound interest calculations in FMP?
JudeAshton Apr 30, 2014 12:49 PM (in response to JudeAshton)The algebra in Excel is FV(rate,nper,pmt,pv,type)
Filemaker is FV ( payment ; interestRate ; periods )
So if anything Excel has more options on there. I have a figure that excel is getting. But we cant recreate the figure with the FV formula on filemaker.
The Excel formula is we need to workout for filemaker is:
=FV 2.5%,10, 0, 2000, 0
In Excel 0, is doing the compound interest. But when I do that in Filemaker we dont get the result.
The result should be: £2,560.17

4. Re: How to do Compound interest calculations in FMP?
philmodjunk Apr 30, 2014 12:55 PM (in response to JudeAshton)The algebra in Excel is FV(rate,nper,pmt,pv,type)
That's not what I'm looking for. That just lists the parameters. The "algebra" is the actual mathematical formula used. This can usually be found in a an applications help file. When I look up FV in FileMaker, I can find the formula that it uses. I've uploaded it as a screen capture from the help file here in this post. If we can put the two formulae side by side, we may be able to derive one that computes what you needeither as a simple calculation or in a custom function. And you can also use that info to search the Brian Dunning web site for a custom function that does this computation as Steve Martino suggested.

5. Re: How to do Compound interest calculations in FMP?
JudeAshton Apr 30, 2014 2:21 PM (in response to JudeAshton)FV = P(1+r/n)^(Y*n)
I think the above is what Excel does.

6. Re: How to do Compound interest calculations in FMP?
JudeAshton May 2, 2014 4:20 AM (in response to JudeAshton)Okay, we resolved the formula.
2000*(1+.025)^10
2000 is the payment or you can point it to a total, 0.25 is the interest rate and 10 is year to retirement.
Thanks for everyones help.