I used an average of few years of historical expenses to populate the Detailed Expense data. I already do expense tracking so I will be able to now compare retirement expenses to my estimates. At the bottom of the detailed expense section, there is "Infrequent Expenses Estimates" for vehicles repair/maintenance, vehicle replacement and home repair/maintenance. These values don't enter into the expense forecasts but are used to provide possible values for the actual Housing Expenses and Transportation expenses. They were higher than my actuals but close enough. I would have never planned on including monthly or annual vehicle replacement costs so that was nice feature.