Calculating your average retirement income depends on a few things. This calculator helps you to determine the amount by inputting your current age, yearly income, age at retirement, monthly wages after retirement, and length of retirement. Other important factors to consider are the age at which you will claim Social Security benefits, and how many and what types of retirement accounts you have. Adjustments are made for inflation, and the calculation does require you to make projections about your future. Keep in mind any tax expenses you may incur based on the type of savings or pension accounts you may have.