1. The 100 Percent Rule. Past analyses have indicated that retirees can live on 70-80 percent of their pre-retirement income. However, given rising medical costs and longer, more active lifestyles, you will most likely need close to 100 percent of your pre-retirement income in retirement.

2. The Two-Thirds Rule. According to the Social Security Administration, Social Security typically provides only about one-third of a retiree's retirement income needs. Therefore, at least two-thirds of your retirement income will need to come from other sources. For example, in 2010, the average monthly Social Security payment for retired workers will total $1,167.10. To generate additional monthly income, you will need other retirement income vehicles, such as a pension or annuity.

3. The 13 Times Rule. To receive guaranteed lifetime income payments by purchasing an annuity, you'll need approximately 13 times the annual income you would like to have in retirement. For example, in order to receive approximately $50,000 per year in lifetime income payments from an annuity, you will need $650,000.

4. The 110 Rule. Historically, as investors age, their portfolios typically include an increasingly higher percentage of fixed investments, and a lower percentage of riskier equity investments. However, given that many Americans are living longer, they may need to keep a higher percentage of assets in equity investments. Utilize the 110 Rule to determine the allocation of your retirement investments by subtracting your current age from 110, and the result is your equity investment allocation. Example: A 65 year-old would have 45 percent (110 minus 65) of his/her portfolio in equity investments. The remaining 55 percent would be allocated to fixed investments. A 75-year-old would allocate 35 percent for equity investments, and the remaining 65 percent to fixed investments.

5. The Rule of 72. Your retirement savings plan should take inflation into account. You can use the Rule of 72 to determine the number of years it will take for your money to be worth half of its current value at a given inflation rate by dividing the inflation rate into 72. With this information, you can structure your plan to include investments that will outpace inflation. For example: To determine how long it will take for your money to be worth half of its current value given a 5 percent inflation rate, divide 5 into 72. The result is 14.4 years.