# Re: calculate interest for one-time payment on loan

• From: John Machin <sjmachin lexicon net>
• To: ken <gebser speakeasy net>
• Cc: gnumeric-list gnome org
• Subject: Re: calculate interest for one-time payment on loan
• Date: Fri, 09 Feb 2007 07:59:17 +1100

```On 9/02/2007 3:37 AM, ken wrote:
```
```Hi, people,

This should be a simple thing to do.  I'm surprised there's not a
function for it.  Or maybe there is one.  I've looked at the FAQ, read
through quite a few of the functions, and searched the archives for this
list and haven't found what I need.  As my Subject line says, I'm
looking for a way to calculate interest for one-time payment on loan.
Too simplistically, it's this:

InterestAmt = DailyInterestRate * NumberOfDays

DailyInterestRate = AnnualInterestRate / 365

NumberOfDays(DateStart, DateEnd)

Gnumeric is nice because variables such as the above can be hardcoded
into a formula or fetched from a cell.
```
```
```
Gnumeric is nice in many respects, but AFAIK that functionality is, and always has been, fundamental to *all* spreadsheet software :-)
```
```
``` I could hardcode everything but
DateEnd; that needs to be fetched from a cell.

Anyone know a way to do this?
```
```
```
Perhaps I'm missing something, but I would have been highly surprised if there were a function supplied for such a short uncomplicated formula.
```
Assuming:
1. your DateEnd value is in cell A1
2. the start date is 31 December 2006
3. the annual interest rate is 7%
then the formula for "interest amount" is
7 / 100 / 365 * (A1 - DATE(2006, 12, 31))
(or something like that) -- isn't it?

HTH,
John

```

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