The cash back credit card calculator is an awesome credit card calculator because all you have to do is move the slider arrows to the dollar amount that you spend every month with your credit card in each of the main spending categories and then the tool will automatically and instantly calculate how much cash back savings you can earn with each of the best cash back credit cards! Different cash back credit cards have different cash back formulas (1% for all purchases, 3%-5% for certain categories, etc.) so enter the amount you spend monthly in each of the following categories to find the best cash back credit card offers!