How does budgeting work?
The budget bar in the right sidebar is the ratio of the total amount you've billed so far against the budget.
If you're scoping the sidebar to your entire project, it will be the total amount billed (rate + any fixed price tasks) against the sum of all the milestone budgets.
If you're scoping the sidebar against a particular milestone, we'll restrict that ratio to just show the total amount billed against the selected milestone's budget.
Note: The budget bar won't be displayed if the sidebar's scope is set to a milestone with no budget.