IRA calculators for determining an account's required minimum distribution are available from the Financial Industry Regulatory Authority, Charles Schwab and Fidelity Investments. The Internal Revenue Service provides worksheets for IRA RMD calculations for both account holders and beneficiaries.
The IRA RMD calculator provided by the Financial Industry Regulatory Authority requires the account holder's balance at the end of the previous year and age at the end of the current year. The calculator for RMDs is based upon the holder reaching the 70 1/2 years of age threshold. People seeking RMD requirements for primary beneficiary spouses over 10 years younger than the initial account holder are directed to the Joint Life Expectancy Table from the IRS. These calculators do not support Roth IRAs.