Instant Financial Conversions.  The Finance Box lets you work out the key information on any financial transaction. For example, suppose you wanted to buy a boat for $10,000 borrowed at 7.5 percent over four years. The Finance Box will tell you your monthly repayments. Let's fill in the information. To work out our repayments we need to enter the $10,000 value of the loan. As we will pay off the loan, we must enter zero as the future value. The interest rate is 7.5 percent over four years, paid at the end of each month. All we need to do next is press the Calculate button to find out our monthly repayment. That tells us that our payments are $241.79 a month for a $10,000 loan repaid fully over four years. The figure is negative because it represents a loss of income.