how much interest do you make on a savings account
And that new total will then earn 6% the following year -- $6.74, another increase. As long as you leave the money in there, it will keep earning more. If you left that same $100 in a 6% interest account for 40 years, you d have $1,028, and your annual interest earnings would be more than $50 per year.The Rule of 72. One simple way to see the power of compound interest is through the rule of 72.nd that new total will then earn 6% the following year -- $6.74, another increase. As long as you leave the money in there, it will keep earning more. If you left that same $100 in a 6% interest account for 40 years, you d have $1,028, and your annual interest earnings would be more than $50 per year.