whereas an annualized rate of return is a rate of return per year, measured over a period either longer or shorter than one year, such as a month, or two years, annualized for comparison with a one-year return. The appropriate method of annualization depends on whether returns are reinvested or not. For example, a return over one month of 1% converts to an annualized rate of return of 12.7% = ((1+0.01)12 − 1). This means if reinvested, earning 1% return every month, the return over 12 months would compound to give a return of 12.7%. As another example, a two-year return of 10% converts to an annualized rate of return of 4.88% = ((1+0.1)(12/24) − 1), assuming reinvestment at the end of the first year. In other words, the geometric average return per year is 4.88%. In the cash flow example below, the dollar returns for the four years add up to $265. Assuming no reinvestment, the annualized rate of return for the four years is: $265 ÷ ($1,000 x 4 years) = 6.625% (per year). Uses Rates of return are useful for making investment decisions. For nominal risk investments such as savings accounts or Certificates of Deposit, the investor considers the effects of reinvesting/compounding on increasing savings balances over time to project expected gains into the future. For investments in which capital is at risk, such as stock shares, mutual fund shares and home purchases, the investor also takes into consideration the effects of price volatility and risk of loss. Ratios typically used by financial analysts to compare a company's performance over time or compare performance between companies include return on investment (ROI), return on equity, and return on assets. In the capital budgeting process, companies would traditionally compare the internal rates of return of different projects to decide which projects to pursue in order to maximize returns for the company's stockholders. Other tools employed by companies in capital budgeting include payback period, net present value, and profitability index. A return may be adjusted for taxes to give the after-tax rate of return. This is done in geographical areas or historical times in which taxes consumed or consume a significant portion of profits or income. The after-tax rate of return is calculated by multiplying the rate of return by the tax rate, then subtracting that percentage from the rate of return. A return of 5% taxed at 15% gives