It depends how your system is setup.
Unlike Microsoft Excel, Airtable does not give us the ability to create formulas that sum data across multiple rows, unless those rows are records in another table that you have linked to your current record in your current table. You can create a SUM of your linked records’ values.
However, if you group your records in the current table, Airtable provides its own built-in summary fields that you can visually see by hovering over the columns that you’re trying to summarize.
If you need more guidance, please include some screenshots of your database.