Free Construction Calculators & Tools/Critical Path Calculator

Critical Path Calculator

Calculate critical path, float times, and project duration from activity networks. Identify critical activities and scheduling flexibility.

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REFERENCE INFORMATION

This tool provides standard reference data compiled from industry sources.

Note:

• Data is provided for quick reference and may not reflect the most current standards or specifications.

About This Calculator

The Critical Path Calculator helps project planners and schedulers perform Critical Path Method (CPM) analysis for construction projects across the UAE and Gulf. Calculate the critical path, total float and project duration from an activity network with finish-to-start links. Identify critical activities that drive project completion and activities with scheduling flexibility.

When to Use This Calculator

  • Identifying activities that control project duration
  • Calculating float to understand scheduling flexibility
  • Analyzing delay impacts on project completion
  • Supporting extension of time (EOT) claims
  • Optimizing resource allocation on critical activities

How to Use This Calculator

1

Define Activities

Enter activity names, durations and predecessors. Links are finish-to-start with no lags.

2

Build Network

The calculator creates the activity network and calculates early/late dates.

3

Identify Critical Path

View the longest path through the network that determines project duration.

4

Review Float Analysis

See early and late dates and total float for each activity to understand scheduling flexibility.

Typical Scenarios in UAE & Gulf Projects

High-Rise Project in Dubai

A planner checks a summary network in days: piling 60, raft 45, typical floors 360, then MEP rough-in 300, façade 240 and interior fit-out 200 in parallel, then testing and commissioning 60. The calculator gives 825 days with the critical path Piling → Raft → Typical floors → MEP rough-in → Testing and commissioning. Façade has 60 days of total float and fit-out 100 days.

Checking a Delay Event in Abu Dhabi

A variation adds 45 days to MEP rough-in, which is critical: the calculator shows the project moving from 825 to 870 days, a 45-day delay. The same 45 days added to interior fit-out, which has 100 days of float, leaves the end date at 825 days. This supports a time-impact discussion under the contract's extension of time clause (FIDIC 1999 Red Book Sub-Clause 8.4; 8.5 in the 2017 edition); concurrency and a full delay analysis are outside this tool.

Frequently Asked Questions

Total Float: Maximum delay without affecting project end date (can affect successors). Free Float: Maximum delay without affecting any successor start dates (more restrictive). Activities with zero total float are on the critical path. This calculator reports total float; work out free float from the successors' early starts if you need it.

Multiple critical paths (near-critical paths with <5 days float) increase schedule risk. Monitor all paths with float less than your risk threshold. Consider adding contingency to near-critical activities. Scheduling software can highlight multiple float paths; this calculator shows the critical path and the total float of every activity, so near-critical activities are those with small float.

FS (Finish-to-Start) is most common (80-90% of relationships). SS (Start-to-Start) used for overlapping activities like floor-by-floor work. FF (Finish-to-Finish) for commissioning/handover sequences. SF (Start-to-Finish) rarely used. Lags represent physical constraints; leads should be avoided per scheduling best practices. This calculator supports finish-to-start links without lags only.

Take Your Calculations Further

This calculator reflects the logic built into Arkan's construction management platform.

Last Updated: January 2026

Standards Reference: Critical Path Method (forward and backward pass), PMBOK Schedule Management

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