Data Type Yes/No (Yes/No field: A type of field with content set to either Yes or No; also known as a Boolean field or a True/False field. For example, the Recurring field indicates whether the task is a recurring task.)
Entry Type Calculated or entered (calculated or entered field: A field in which the value is determined by Project based on information in other fields. Information that you enter in the field yourself overrides calculated values.)
Description The Estimated field indicates whether the task's duration (duration: The total span of active working time that is required to complete a task. This is generally the amount of working time from the start to finish of a task, as defined by the project and resource calendar.) is flagged as an estimate (estimated duration: A duration for which you have only enough information to determine a tentative value. So that its status is clearly visible, an estimated duration is clearly marked by a question mark immediately following the duration unit.). The Estimated field contains Yes if the task duration is an estimate and No if it is a set duration. You can change whether a duration is estimated or set by choosing Yes or No in the Estimated field.
How Calculated By default, when you first add a new task, it is given an estimate of one day, and will appear in the Duration field as "1 day?". At any time, if you add a question mark (?) after any duration in the Duration field, the duration is an estimate. If you remove the question mark, the duration is considered set.
Best Uses Add the Estimated field to a task sheet when you want to view or change whether a task duration is estimated. Add this field when you want to sort, filter, or group for whether tasks have estimated durations. Sorting, filtering, or grouping based on the Estimated field can be helpful when you want all the estimated duration tasks to be displayed together so you can change the estimates to set durations.
Example You're building a new schedule using estimated task durations, and you've been entering set durations as you receive input from the resources. You want to see which of the tasks still have estimated durations. Add the Estimated field to the Entry table of the Gantt Chart view.
Remarks You can also indicate whether a task has an estimated duration in the Task Information dialog box.
By default, when you first add a new task, it is given an estimate of one day. If you don't want this one-day duration to be an estimate, you can change this option in the Project Options dialog box.
Also by default, a question mark appears with any estimated duration in the Duration field. You can hide the question marks for estimated durations in the Project Options dialog box.
You can also filter for tasks with estimated durations by using the Tasks With Estimated Durations filter.