This thread may help you out.

Unfortunately, trying to implement your example would trigger Airtable’s safeguards against circular references. That said, there are ways to get around this limitation, although they require eminimal] manual intervention. In an earlier post and demo base, I show how to create several different types of running totals. Admittedly, none is very pretty; on the bright side, you can often drop the provided routines into your base and henceforth forget about them…