figuring interest and showing the rate

I'm trying to get excel to total the amount of interest to add-on to a Small claims judgement, i need to get it to show me the starting total, say $4321 x plus 10% annually. and then i want to enter the date the interest start and the day the interest stopped counting, then the total per day amount of interest.

Hello JustCofox,

The basic formula for simple interest is Interest Amount = Principal x Rate x Interval

It isn't clear to me if you want the simple interest or interest on the declining balance. You state you want the total daily amount of interest which makes me think you are referring to compound interest. Can you clarify the interest calculation you want to use?

Sincerely,
Leith Ross

on the assumption that interest is 10% per year compound

interest is

4321 x 10/100 x days / 365

Annual Compound Interest Formula

P = Principle Investment.
r = Interest Rate.
R = ( 1 + r) .
Sumn = Sum at the end of the nth Term.
n = Number of periods (Yrs,Mths, Days).

NB:- If period = days and interest rate is Annual then :-
n = number of days /365

Invest Sum "P" compounded at interest rate (1+ r) = "R" for "n" yrs.
Sumn = P(1 + r) ^n or Pr ^n

Example:- Invest £4000 for 500 days @ annual interest of 10% = 0.1

Sumn = 4000*(1+0.1)^(500/365) = £4557.87

Use this formula in your Spreadsheet

Regards Mick