Task Dependency Duration calculator.
Separate parallel tasks and predecessor chains from the sum of all working hours.
Your inputs
Use measurements from your plan and properties from your chosen product. Any prefilled values are illustrative.
A clear estimate starts here.
Enter your dimensions and product details to see the quantity and purchase breakdown.
Formula and assumptions
How this calculation works.
Task numbers follow entry order. Dependencies must point backward to prevent cycles, and each dependent task starts at its predecessor’s finish.
A worked example
Illustrative inputs only. Product properties and design dimensions are not recommendations for your project.
- Entered task duration
- 3 hours
- Predecessor task number; zero for none
- 0
- Entered task duration
- 4 hours
- Predecessor task number; zero for none
- 1
- Entered task duration
- 5 hours
- Predecessor task number; zero for none
- 0
Unconstrained earliest completion: 7 hours
One finish-to-start predecessor per task; zero means none. Assumes unlimited parallel resources. This is not a resource-feasible crew schedule or a promise of completion time.
Before you purchase
Use dimensions from your plan and properties from your chosen product. Any design spacing, section or fixing pattern must already be specified.
Task numbers follow entry order. Dependencies must point backward to prevent cycles, and each dependent task starts at its predecessor’s finish.
Dimensions, quantities, prices, timing and product properties are supplied by you. This tool does not select construction specifications or assess structural, electrical or hydraulic suitability.
Method: dimensional arithmetic and user-supplied specifications. Software checks: 2026-10-04. Calculation and review policy.