Information needed to use AARP's Fixed Annuity Calculator include the starting balance, the annual contribution, current age of the contributor and anticipated withdrawal age, notes AARP.org. The user must also know the current tax rate, the retirement tax rate and the taxable account's return percentage. The initial interest rate, the years the initial interest rate is guaranteed, the expected average interest rate and the minimum guaranteed rate must also be known to perform calculations using the tool.
AARP provides a detailed explanation for each of the factors that must be input in order to use its calculator. For example, the starting balance listed on the calculator is the initial amount that the contributor wants to put into the fixed annuity, notes AARP. The withdrawal age is the anticipated age that the contributor wishes to withdraw the balance of the annuity.
The user can also list the surrender charges using the calculator for a more defined result, although it is not necessary to enter this information to use the tool. When provided, the user should list the surrender charge for the first five years as a percentage. The calculator automatically enters all zeroes in these fields if the surrender charges are unknown.