Gantt Chart Duration Calculator

Summary

Add tasks with start dates and durations, toggle weekend exclusion, and see the full project timeline with end dates instantly.

How it works

1. Enter a task name, start date, and duration in days.
2. Toggle "Working days only" to exclude Saturday and Sunday from duration counts.
3. Click "Add Task" to append it to the task list.
4. The calculator computes the end date for each task automatically.
5. See the full project span — earliest start to latest end — at the bottom.
6. Export the task list as a CSV for use in Excel, Notion, or any Gantt tool.

Use cases

• Plan a software sprint by adding individual feature tasks with their estimated durations.
• Calculate a realistic project deadline after accounting for weekends.
• Identify how tasks overlap or chain together in a multi-phase delivery plan.
• Generate a quick CSV to paste into a spreadsheet-based Gantt chart.
• Re-baseline a project schedule after a scope change by adjusting durations.
• Check whether a client deadline is achievable given today's start date.

Frequently Asked Questions