Helpful Toolbox

Project Timeline Calculator

Enter your project start date and a list of phases with durations in days. The calculator schedules each phase back-to-back and instantly shows every phase's start and end date, the total span, and your project end date — with an option to skip weekends.

📖 How it works & FAQ

Plan a project schedule in seconds

Every project plan starts with the same two questions: when does each phase happen, and when does the whole thing finish? This project timeline calculator answers both instantly. Pick a start date, list your phases with a duration in days for each, and the tool chains them together back-to-back — the first phase begins on your start date, and each following phase begins the day after the previous one ends. You get a clean schedule table with a start and end date for every phase, plus the overall project end date.

Everything runs privately in your browser. Nothing you type is uploaded, saved, or shared, so it is safe to sketch out client work, internal roadmaps, or personal projects.

Calendar days or working days

The day-counting selector changes how durations are measured. In calendar mode, a 10-day phase spans 10 consecutive days including weekends. In working-days mode, weekends are skipped: durations count only Monday through Friday, phases never start or end on a Saturday or Sunday, and a start date that lands on a weekend rolls forward to Monday. Working-days mode is usually the better match for office projects, while calendar mode suits construction curing times, marketing campaigns, or anything that runs seven days a week.

How to use it

  1. Set your project start date — it defaults to today.
  2. Choose calendar days or working days for how durations are counted.
  3. Edit the sample phases: rename them and set each duration in days.
  4. Click + Add phase for more rows, or the × button to remove one.
  5. Read the results: project end date, total span, and the full phase-by-phase schedule update live as you type.

FAQ

Do phases overlap?
No. This calculator models a sequential (waterfall-style) plan where each phase starts the day after the previous one ends. To model overlap, merge overlapping work into a single phase or shorten a duration.
Is the end date inclusive?
Yes. A 1-day phase starts and ends on the same date, and a 5-day phase starting Monday ends Friday. The total span counts both the first and last day.
Does working-days mode handle holidays?
It skips Saturdays and Sundays only. For public holidays, add an extra day to the affected phase's duration.
Can I save my timeline?
The tool does not store data, which keeps it private. Screenshot the schedule table or copy it into your document; your inputs recalculate instantly if you re-enter them later.