Delivery Date Predictor Calculator

Estimate finish dates with workload, velocity, and buffers. Track confidence, holidays, efficiency, and dependency delays. Plan commitments with clearer timelines for every project milestone.

Project delivery input form

The page stays single-column, while the calculator uses 3 columns on large screens, 2 on smaller screens, and 1 on mobile.

Example data table

These sample rows illustrate how workload, velocity, and risk conditions influence the forecast.

Scenario Total Units Completed Velocity/Day Efficiency Risk Buffer Rework Working Days/Week Predicted Finish
Website Relaunch 240 96 12 88% 15% 8% 5 Baseline: 42 days from status date
ERP Migration 420 210 14 82% 20% 10% 5 Baseline: 55 days from status date
Mobile App Rollout 180 120 11 92% 10% 4% 6 Baseline: 18 days from status date

Formula used

Remaining Scope = Total Scope − Completed Scope

Effective Velocity = (Average Daily Velocity × Team Efficiency) ÷ Complexity Index

Adjusted Remaining Scope = Remaining Scope × (1 + Scope Change) × (1 + Rework) × Complexity Index

Base Workdays = Adjusted Remaining Scope ÷ Effective Velocity

Total Buffer Days = Risk Buffer Days + Confidence Buffer Days + Manual Buffer Days

Baseline Calendar Days = (Baseline Workdays × 7 ÷ Working Days Per Week) + Dependency Delays + Holidays

Predicted Delivery Date = Status Date + Baseline Calendar Days

On-Time Probability is a weighted planning score using progress, efficiency, risk, rework, scope volatility, and dependency pressure.

How to use this calculator

Enter the project name, start date, status date, and optional target due date.

Provide total scope units and completed units. Use tasks, tickets, points, pages, or any consistent measurement.

Add average daily velocity, team efficiency, rework, expected scope change, and complexity index.

Include dependency delays, holiday days, working days per week, confidence level, and manual buffer.

Press Predict delivery date. Review baseline, optimistic, and conservative dates. Then download the results as CSV or PDF.

Frequently asked questions

1) What should I use as scope units?

Use one consistent unit across the project. Tasks, tickets, story points, deliverables, pages, or test cases all work if total and completed scope use the same unit.

2) What does the complexity index change?

The complexity index adjusts productivity. Values above 1.00 reduce effective velocity because each unit needs more effort. Lower values indicate simpler work.

3) Why include rework percentage?

Rework captures fixes, revisions, approvals, retesting, and defect cleanup. Higher rework increases the adjusted remaining scope and usually pushes delivery later.

4) What is the difference between risk buffer and manual buffer?

Risk buffer is calculated from uncertainty. Manual buffer is an additional management cushion added for governance, external approvals, leadership expectations, or special events.

5) How is on-time probability estimated?

It combines completion progress, efficiency, delays, rework, complexity, scope volatility, and target-date variance. Treat it as a planning signal, not a promise.

6) Can I leave the target due date empty?

Yes. The calculator still predicts delivery dates. Without a target, it labels schedule condition using internal performance and risk signals only.

7) Which date starts the forecast?

The status date starts the prediction window. The project start date helps show elapsed time and provides useful context for project progress.

8) When should I update the inputs?

Update the values whenever scope, staffing, velocity, dependencies, or holidays change. Frequent refreshes improve planning visibility and stakeholder reporting quality.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.