Total budget - sum of another column


Hello. Ok I get that airtable is a database and not a spreadsheet. I get that you cannot calculate based on cells and I like that. What I need to do is sum one column, and subtract that increasing sum from another column’s total budget. So if I have 5000$ and i invoice 1000$ and then 2000$, then i would like it to add up the 1000$ and 2000$ and tell me I have 5000$ - 3000$ remaining.

I know this is possible somehow?! Right now i am using the summary bar which is better than nothing, I need to put it into excel to send to someone (summary bar doesnt download when you transfer data)