# Compounding interest calculation

• Vajko
Asked on November 04, 2021 at 11:22 PM

Hey everyone,

I'm trying to get the following compounding interest calculation to work in my form but I'm stuck.

P [(1 + i)n – P]

The place where I'm trying to calculate this is field "whatYou65" in the form. You can see this is a Form Calculation field.

Here's the thank you page where I've broken down all of the calculations from the form. Everything with a green check mark is correct. But the 5-year compounding formula I'm trying to create doesn't work correctly. Do note that the formula references two other calculated fields:

1. One year as-is (oneYearasis)
2. One plus percent increase (onePlus)

I did this because I wanted to separate these separate calculations out of the formula so it wouldn't be too complicated but I suspect that this is where the problem lies.

Also for reference, the only three data fields I'm using to get this info and the data I'm using. Don't worry about filling out all of the fields to troubleshoot the form:

1. What was the average yearly increase of your health insurance plan over the past 5 years? (10%)
2. What state are you primarily located in? (Wyoming)
3. What is the total amount you pay to your insurance company every month? (\$10,000)

• Richie
Answered on November 05, 2021 at 06:19 AM

I'm not sure if my calculation is correct however, kindly check my sample form https://form.jotform.com/213082560918052

You can also check my calculation by cloning my form.

Let us know how it goes.

• Vajko
Answered on November 05, 2021 at 09:37 AM

Hi Ritchie, thanks for your help. Your form isn't taking into account the same calculations. I'm actually quite lost by what you've put together as it doesn't match the fields in mine so I don't know what each field does.

• Richie
Answered on November 05, 2021 at 11:17 AM

Hello, I was following the formula you have shared which is P [(1 + i)n – P] However, can you please explain further the formula and calculation in your form for me to check again?