Hi @CottageKeeper - you can’t get Airtable to automatically make the value negative in a single field. But what you could do is have an “entry” field and a “value” field:
The “Expense entry” field is just for data entry and the value field is what gets used in your base, calculations, formulas and so on. The formula I have in this field is:
IF({Expense entry}, {Expense entry} * -1)
The expense entry field can be hidden in the views where it doesn’t make sense to show it.