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Float & Critical Path Calculator
Define your activities, durations, and predecessors. Get Early Start / Early Finish / Late Start / Late Finish, Total Float, Free Float, and the Critical Path in one click. Uses standard CPM forward and backward pass.
Activities
Use short IDs (A, B, C… or 10, 20, 30). List predecessors as comma-separated IDs. The Start activity has no predecessors.
ID
Name
Duration
Predecessors
Results
Critical activities (Total Float = 0) are highlighted in gold.
Add activities above, then press Calculate.
How CPM works
Forward pass = ES = max(EF of predecessors), EF = ES + Duration
Backward pass = LF = min(LS of successors), LS = LF − Duration
Total Float (TF) = LS − ES = LF − EF
Free Float (FF) = min(ES of successors) − EF
Critical Path = activities with Total Float = 0
Project Duration = EF of the last activity
Working with real EPC schedules? Learn Primavera P6 with real project datasets.
See Primavera P6 curriculum