Free Online Tool
Project Duration Calculator
Plan multi-activity projects with automatic duration calculation and a Gantt-style timeline. Count all days or workdays only, see your overall project span, and export to CSV.
Try it now
Free — no sign-up required
| Activity | Start Date | End Date | Days | ||
|---|---|---|---|---|---|
| — |
Examples
Real-world calculations
Q.My project has 4 phases. How long is the whole project?
A.Add each phase as an activity row. The summary bar shows the overall start, end, and total span automatically.
Q.How many workdays does a 3-month project span?
A.Enter the start and end dates in workdays-only mode. A Jan–Mar project is roughly 65 working days.
Q.I need to plan a website launch: design, development, QA, and launch. How do I visualize it?
A.Add each phase as a row with dates. The Gantt chart renders all four as proportional bars on a shared timeline.
Q.My sprint is 2 weeks. How many working days is that?
A.A 2-week sprint (Mon–Fri) = 10 working days. Enter the sprint start and end to confirm.
Q.How long is a project that runs from Feb 1 to Aug 31?
A.211 calendar days, or approximately 152 working days (Mon–Fri), excluding federal holidays.
Q.Can I export my project plan to share with my team?
A.Yes — click Export CSV to download a spreadsheet with all activities, dates, and durations.
How it works
Simple, accurate, instant.
Add your project activities
Enter a name, start date, and end date for each activity or phase. Add as many rows as you need.
Choose your counting mode
Select All Days, Workdays Only (Mon–Fri), or Weekends Only. The duration column updates instantly.
View the Gantt timeline
Once you have 2+ activities with dates, a Gantt-style chart renders automatically showing relative durations and overlaps.
Review the summary and export
The summary bar shows overall project start, end, and total span. Export to CSV for sharing or further planning.
FAQ
Frequently asked questions
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