ROI is Rate of Investment. It is a ratio between the net gain and the net cost of an investment. It is also known as ROR (rateofreturn), this calculator allow you to compare the results of different investments over different time duration. ROI is the rate of return you expect which is annually compounded from your investments before all taxes.
To calculate ROI, difference of the gain (or return) from an investment and cost of the investment is divided by the cost of the investment. The result is known as a percentage or a ratio of return.
ROI = 

ROI = 

× 100% 