It’s common to discuss desired annual retirement income as a percentage of your current income. Depending on who you’re talking to, that percentage could be anywhere from 60% to 90%, or even more. The appeal of this approach lies in its simplicity. The problem, however, is that is doesn’t account for your specific situation. To determine your specific needs, you may want to estimate your annual retirement expenses.

Use your current expenses as a starting point, but note that your expenses may change dramatically by the time you retire. If you’re nearing retirement, the gap between your current expenses and your retirement expenses may be small. If retirement is many years away, the gap may be significant, and  projecting your future expenses may be more difficult.

Remember to take inflation into account. The average annual rate of inflation over the past 20 years has been approximately 2.6 percent. (Source: Consumer price index (CPI-U) data published annually by the U.S. Department of Labor, 2011.)

And keep in mind that your annual expenses may fluctuate throughout retirement. For instance, if you own a home and are paying a mortgage, your expenses will drop if the mortgage is paid off by the time you retire. Other expenses, such as health-related expenses, may increase in your later retirement years. A realistic estimate of your expenses will tell you about how much yearly income you’ll need to live comfortably.