The Estimates tab shows a summary of planned revenue and costs, based on the linked Project Estimates document.
If the project status is New, the following buttons are available:
Create New Estimates – Allows users to enter planned revenue and cost details for the project.
Create Budget – Let users create a budget based on the entered estimates.

If the project has a different status (e.g., Active), the tab shows these buttons instead:

The Method of Calculation appears based on the option selected in Project Costing Settings, determining how project revenue and cost estimates are calculated and displayed.