The Estimates tab displays a summary of planned revenue and cost details pulled from the linked Project Estimates document.
Edit Current Estimates – Enables modification of the existing budget details within the current estimate version.
Create Variation Order – Used to record and apply approved changes or additions to the original scope and budget.
Create Budget – Initiates a new budget if none currently exists for the project/if exist, it will allow amending it.

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.