Running total for monthly budget

[B11]

hi, I’m new to airtable and not much of a techy person so even when I read some of the comments for how to do a running total, I’m still so lost…
I’m trying to create a monthly roll up to see how much money I should have at the end of each month but rolling up from the last month total. I am able to get as far as getting the Income - Expenses = Total but I tried using Previous Row function to get last row total to try to add it to next month’s total but it tells me it causes a circular reference.
Or is there a way to add last month’s total with this month’s income? I’m at my end on trying to get a running total. HELP anyone…
here is the view of the table… I need the previous row to be the last column roll up. I can’t set it up since it gives me circular error so only been able to use Delta for previous row to test it but it’s not the right value I need for the running total. how can I get the last column to be the running total?

[Mohamed_Swella2]

Hi @B11 ,

You should take the last Field (Total Remaining) in the Previous Row Delta instead of the Delta field. This way it will give you the correct number.

[kuovonne]

Airtable cannot do running totals with just formula fields. There are some extremely complex systems for doing rollups that were created a few years ago, but they do not scale well, can slow down your base, and are no longer recommended.

Instead, I suggest you look into the scripting. There is a running total example script.