Budgeting & pacing
Planned spend to date
Planned spend to date is the amount a campaign should have spent by a given day according to the approved plan. For flat flights it is budget multiplied by elapsed days over total days; for weighted flights it is the sum of the approved daily or weekly weights so far.
In practice
This number is the baseline that makes pacing meaningful. Get it wrong and every downstream figure - variance, required daily spend, projections - inherits the error.
The most common mistake is applying a straight-line calculation to a shaped flight, which produces false alarms on front-loaded campaigns and hides genuine drift on back-loaded ones.