Calculate when you will become a millionaire
This calculation will find out when you will become a millionaire (in any given currency) considering your current income (profit per month).
Calculate compound interest
Compound interest is interest upon interest that will build up to create great wealth (or debt!) over time. This calculation will help you calculate how much you will gain through compound interest.
What is the current worth of your passive income?
If you have a website (or similar) that provide you with passive income, this calculation will help you calculate the current worth of your future income. You can use it to estimate a selling price.
This is the head category of all the different finance and economy related calculations on this site. Don't forget to check out the subcategories as well if you can't find what you are looking for.