Calculator Inputs
Large screens show three columns, medium screens show two, and mobile uses one column.
Example Data Table
| Item | Example Value | Why It Matters |
|---|---|---|
| Deliverables | 6 | Defines the main outputs to break down. |
| Tasks per Deliverable | 8 | Creates the estimated total leaf-task count. |
| Hours per Task | 5 | Converts scope into baseline effort. |
| Complexity / Dependency | 1.15 / 1.08 | Adjusts baseline effort for technical and coordination drag. |
| Rework / Overhead / Contingency | 7% / 12% / 10% | Adds revision time, management load, and risk reserve. |
| Team / Productive Hours | 5 people / 6.5 hours | Converts effort into person-days and duration. |
| Max Tasks per Package | 6 | Guides package sizing for ownership and control. |
| Sample Output Snapshot | 48 tasks, 8 packages, about 381.58 total hours | Shows a realistic work breakdown summary. |
Formula Used
1) Total Tasks
Total Tasks = Deliverables × Tasks per Deliverable
2) Base Hours
Base Hours = Total Tasks × Average Hours per Task
3) Adjusted Execution Hours
Adjusted Execution Hours = Base Hours × Complexity Factor × Dependency Factor × (1 + Rework %)
4) Overhead Hours
Overhead Hours = Adjusted Execution Hours × Overhead %
5) Contingency Hours
Contingency Hours = (Adjusted Execution Hours + Overhead Hours) × Contingency %
6) Total Effort Hours
Total Effort Hours = Adjusted Execution Hours + Overhead Hours + Contingency Hours
7) Person-Days
Person-Days = Total Effort Hours ÷ Productive Hours per Person per Day
8) Duration Days
Duration Days = Person-Days ÷ Team Size
9) Work Packages
Recommended Work Packages = Ceiling(Total Tasks ÷ Maximum Tasks per Package)
10) Phase Allocation
Phase Hours = Total Effort Hours × Normalized Phase Percentage
Phase percentages are normalized automatically, so any positive set of phase inputs can still allocate 100% of total effort.
How to Use This Calculator
- Enter the project name, deliverable count, task density, and average task hours.
- Set complexity, dependency, and rework values to reflect delivery difficulty.
- Add overhead and contingency percentages for management effort and risk reserve.
- Enter team size, productive daily hours, and your preferred maximum tasks per package.
- Distribute effort across phases such as design, build, test, deployment, management, and closure.
- Press Calculate Work Breakdown to show results above the form.
- Review summary metrics, the phase table, and the Plotly chart.
- Use the CSV or PDF buttons to export the calculated output.
FAQs
1) What does this calculator estimate?
It estimates total tasks, work packages, effort hours, person-days, duration, and phase-wise allocation using scope, effort drivers, team capacity, and reserve assumptions.
2) Why use complexity and dependency factors?
They adjust baseline effort for technical difficulty and coordination friction. Projects with multiple approvals, integrations, or specialist handoffs usually need values above 1.00.
3) What is a good maximum tasks per package?
A smaller package size improves ownership and tracking. Many teams use four to eight tasks per package, depending on reporting needs and delivery cadence.
4) Are overhead and contingency the same?
No. Overhead covers expected coordination work. Contingency is a reserve for uncertainty, risk response, or unplanned work that may or may not happen.
5) Why use productive hours instead of eight hours?
Because meetings, messages, reviews, and admin reduce pure execution time. Productive hours create more realistic schedules than assuming every working hour is available.
6) What happens if phase percentages do not equal 100?
The calculator normalizes any positive phase mix to 100%. That keeps the allocation usable while preserving your intended proportional distribution.
7) Does the duration output guarantee completion time?
No. It is a planning estimate based on averages. Real delivery depends on availability, sequencing, approvals, blockers, and execution quality.
8) Can this be used for agile and waterfall projects?
Yes. Use it for release planning, statement-of-work scoping, sprint roadmap framing, or traditional WBS estimation. The inputs are method-agnostic.