topic Re: Percentage Change Calculation in ArcMap Questions

Percentage Change Calculation

MichelleCouden — Fri, 12 Jun 2020 20:12:50 GMT

Trying to calculate percentage change in numbers from year 2019 to 2020. The calculation in the field calculator should be 2020 - 2019 = divided by 2019. I have tried several ways but it is not showing the correct answer. Here is what I have 4244 - 6363 = -2119 / 6363 shows -.33 percent change. [Volume_2020] - [Volume_2019] / [Volume_2019] but it gives me the answer of 4243. Am I missing same quotations?

Re: Percentage Change Calculation

GeoJosh — Fri, 12 Jun 2020 20:43:32 GMT

Hi Michelle,

The first portion of the formula needs to be in parentheses like this:

([Volume_2020] - [Volume_2019]) / [Volume_2019]

Otherwise, the division will be performed before the subtraction due to order of operations. Let me know if this works!

Best,

Josh

Re: Percentage Change Calculation

MichelleCouden — Fri, 12 Jun 2020 20:52:11 GMT

Thanks. I was using brackets not parentheses. I’ll try that.

Re: Percentage Change Calculation

MichelleCouden — Mon, 15 Jun 2020 14:50:35 GMT

It didn’t work. It said it didn’t like the Type Mismatch.

Re: Percentage Change Calculation

MichelleCouden — Mon, 15 Jun 2020 15:14:35 GMT

It worked. For some reason, it was not working inside my geodatabase. So I took it out and then did the calculation. Thanks for the help.