Calculate Amount Due plus Late Fees plus Interest

Scenario:

1. Klem has 15 days to pay a $75 fine. Day 16 rolls around and Klem didn't pay.

2. Klem is assessed a $15 late fee and 15% interest begins on the late amount, $75.

3. 30 days later, Klem still has not paid. Another $15 late fee added and the unpaid balance is now $90 plus whatever the amount of interest is on the $75, $11.25? (not sure I calculated correctly but it will serve as an example)

Explanation: The amount of interest $11.25 on the first $75 needs to be added to the $75 creating the new unpaid balance or $86.25. on which 15% interest is charged as the new unpaid balance. The $15 additional fine is added to the unpaid balance, $86.25 + $15 to become the new amount due, $106.25.

4. Klem, however, is bull headed and refuses to pay within the next 30 days. Thus, the scenario repeats so the new past due amount is $106.25 + the interest ($12.94) accumulated on the past due amount of $86.25. Now, add the $15 late fee and the total amount due is $114.19.

5. Yoo-Hoo, Hey Klem. This is starting to add up. But, Klem goes another 30 days. The amount due, $114.19, is now the past due amount so, $114.19 + 15% interest $17.24 = the new past due amount $131.43, + another $15 late fee becomes the new amount due $146.43 and 15% is being added each day to the past due amount

For some, the cycle may repeat every 30 days and, believe it or not, may stretch into a few years. Ok miracle workers, have at it. I know you’re capable of figuring this out but is Jotform capable?  I sure hope so. I can use the miracle calculation.

UPDATE: I looked up the formula and it's really not that hard. The question is, can Jotform calculate this formula?

Determine Daily interest Rate     Annual interest Rate .15% / 365 = $.041 daily rate

$75 is incurred on Jan 1, net 30 days or due 1/30. Payment is missed

For the 1st 30 day cycle, Multiply .041 by average daily balance $75 = $3.08 interest due. Add late fee $15 + $75 + $3.09 = New amount due $93.08

At the end of the 2nd billing cycle, the average daily balance is $92.08 repeat the formula

Ave. daily balance $92.08 * .041 = $3.78 + late fee $15 =$110.86 Total amount due

Repeat every 30 days. The average daily balance does not change because there are no credits or debits.

You can perform a calculation with the Form Calculation widget or conditional logic. 

How to Perform Form Calculation Using a Widget

How to Insert Text or Calculation into a Field Using Conditional Logic

You can calculate the number of days and then based on the number of days use a different formula to calculate the total amount due. 

Thank you very much. I'm looking forward to putting this together. It should be fun.