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Calcimator

Critical Path Calculator

Calculate critical path duration, ES, EF, LS, LF for project activities.

Inputs

days
days
days
days
days

Results

Critical Path Duration

25 days

Path A Duration (1→2→4)23 days
Path B Duration (1→3→5→4)25 days
Path A Float2 days
Path B Float0 days
Critical Path is B (1=Yes)1
Avg Activity Duration6.6 days
A1EF5
A1LF5
How to Use This Calculator
  1. Enter the duration and dependencies for each task in the project.
  2. The calculator identifies the longest path through the network.
  3. Review the critical path tasks — any delay here delays the entire project.
  4. Use float (slack) values for non-critical tasks to optimize resource allocation.
  5. Update the schedule regularly as tasks complete and durations become known.

How the result changes with Activity 4 (End)

Activity 4 (End)Critical Path Duration
100115 days
350365 days
650665 days
900915 days

What each input means

Activity 1 (Start)
Duration of the starting activity (on both paths).
Activity 2 (Path A)
Duration of Path A middle activity.
Activity 3 (Path B)
Duration of Path B first middle activity.
Activity 4 (End)
Duration of the ending activity (on both paths).
Activity 5 (Path B)
Duration of Path B second middle activity.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Activity 1 (Start) = 5, Activity 2 (Path A) = 8, Activity 3 (Path B) = 6, Activity 4 (End) = 10 = 5 input(s) provided
  2. Calculate Critical Path Duration
    Critical Path Duration
    25 = 25
  3. Calculate Path A Duration
    23 = 23
  4. Calculate Path B Duration
    25 = 25

Engine last updated . Checked against 2 independently-derived tests — how we verify calculators.

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