LibreOffice Calc

LibreOffice Calc is a free, open-source spreadsheet application that works offline, so you don't need internet to track your budget. It opens and saves Excel files, so you can use spreadsheets you've already created or download budget templates in standard formats.

Since everything runs locally on your computer, there are no subscriptions or online accounts required. It's a solid choice for people who want complete control over their budgeting data.