The Rule of 72 is another way to make estimates about compound interest quickly. You might even try using an Excel formula. To calculate compound interest use the formula below.
The Rule of 72 is another way to make estimates about compound interest quickly.
2 Gather variables the compound interest formula. N Number of Periods. The P in the formula above stands for your principal thats the amount that you start with. In the formula A represents the final amount in the account after t years compounded n times at interest rate r with starting amount p.