I am trying to compound principal and interest at a variable percent a day to reach a maximum return of 100%. The interest stays in the account and the principal is subtracted once the interest reaches 100%.

New money can be added at any date. Once the new money reaches 100% return I would like it to be subtracted from the principal.

Here is an example:

Day 1 start with $500. Interest rate is 1% a day. In 100 days it will reach 100% interest. On Day 7 $300 is added and in 100 days it will reach 100% interest. So on Day 7 the Principal balance increases by $300.

Column-A Row-1 starts with a balance of $500.00 and multiplies the interest from Column-B Row-1 (1.00%) and the result in Column-A Row-2 is $505.00. Now the $5.00 in interest becomes Principal on day 2 until it reaches a 100% return.

As you see, the daily interest is compounded as well and when the interest amount earns 100% from the day it was applied then I would like to subtract it from the accumulated principal balance in 100 days.

Now here is the catch, the interest rate can change daily. Day 1 = 1%, Day 2 = 1.5%, Day 3 = 1.75%, Day 4 = 0.50%.

What I would like to know how to program is as the interest rate is added daily is there any amount in Principal or compounded interest that has reached 100% and then subtract it from the running Principal balance.

And if at all possible keep a running total of interest earned until it reaches a minimum reinvestment incriment of $10.00.

I would be willing to pay a reasonable amount for someone to help me code this.

Here is some code


(C,21) =C20+E20+M20 (Accumulated Principal and Interest)
(C,22) =C21+E21+M21

(E,21) =C21*D21 (Accum Principal and Int * Int Rate)
(E,22) =C22*D22

(M20) = (Entry of Principal amount, Example- $300)



Thank you,
Stevej