Compounding Interest does some interesting things. It is powerful when you have positive returns and powerful when you have negative returns. This calculation allows you to enter up to 20 annual return numbers. It then calculates the cumulative return and the average return in three ways -- first the numeric average of the numbers you enter, and then the cumulative return divided by the number of years, and finally by taking the cumulative return and finding the single rate that would compound to that cumulative amount over your time period. You can enter zero or positive or negative numbers for returns. 1: % 11: % 2: % 12: % 3: % 13: % 4: % 14: % 5: % 15: % 6: % 16: % 7: % 17: % 8: % 18: % 9: % 19: % 10: % 20: %