calculating interest payments on a loan for an indefinite period

[spudsnruf]

I borrow money for my small biz on an indefinite period., and I cant get the
answer I need bu usng Excel 2003's interest rate calculations, as this seems
to only work if there is a defintie period of time.
example:

I borrow £10 at a rate of 1% for every 14days.
Typically I repay it at anytime between 14 and 90 days.
So i want to be able to know how much interest I am clocking up on 14 day
basis.

Advice always welcome!
Thank you

 

[Bernard Liengme]

day zero you owe £10
14 days from now you will owe 10*(1+1%)
28 day from now you will owe 10*(1+1%)*(1+1%) = 10*(1+1%)^2
42 day later 10*(1+1%)^3
In 90 days you will owe 10*(1+1%)^(90/14)

Just think back to those fun arithmetic classes.
best wishes

 

[spudsnruf]

Thank you Bernard. I was always the one in the maths class facing the wall
for some thing done at the beginning of the class. If i understand your
suggestion corectly, this wont tell me the answer on any given day
automatically though twill it? My plan was to be able to look at my
spreadshet on a daily basis and be able to see what the accumalated interest
is on each loan to the current day. I have about 120 of these small loans
owing at any one time, and so keeping track of them by just knowing the
amount owed on each loan up to the day I look at them is what I wanted to do.
Does this make sense? Is this possible? Thank you.

 

[Bob I]

Another question is: Is the interest compounded?

Thank you Bernard. I was always the one in the maths class facing the wall
for some thing done at the beginning of the class. If i understand your
suggestion corectly, this wont tell me the answer on any given day
automatically though twill it? My plan was to be able to look at my
spreadshet on a daily basis and be able to see what the accumalated interest
is on each loan to the current day. I have about 120 of these small loans
owing at any one time, and so keeping track of them by just knowing the
amount owed on each loan up to the day I look at them is what I wanted to do.
Does this make sense? Is this possible? Thank you.

:

 

[spudsnruf]

Hi...no the interest is not compounded. its just a fix % every period
(usually 14 days). Thank you. Did my question make sense? Cheers

 

[Bob I]

Divide the total number of days in question by 14 and that's the current
percentage.