Free calculator
When does the plan actually land?
Most project templates draw the tasks you typed. This one works out the date. Say how long each task takes and what it waits for, and the finish date comes back — with the number of days you have left against the date you promised. It runs in your browser and nothing is sent anywhere.
| # | Task | Waits for | Days | Start | Finish |
|---|---|---|---|---|---|
| 1 | Sep 8, 2026 | Sep 12, 2026 | |||
| 2 | Sep 13, 2026 | Sep 22, 2026 | |||
| 3 | Sep 13, 2026 | Sep 24, 2026 | |||
| 4 | Sep 25, 2026 | Oct 9, 2026 | |||
| 5 | Sep 23, 2026 | Sep 28, 2026 | |||
| 6 | Oct 10, 2026 | Oct 14, 2026 | |||
| 7 | Oct 15, 2026 | Oct 21, 2026 | |||
| 8 | Oct 22, 2026 | Oct 22, 2026 |
Change any duration and watch the dates below move. “Waits for” takes the number of a task above this one, or 0 for none — the same constraint the workbook has, and what lets the dates work themselves out without a macro.
Project finishes
Oct 22, 2026
11 days of slack against the date you promised.
Task #8 sets the finish date. Shorten anything else and the date does not move.
What each row is waiting on
- #2 Write the copy — Waits on #1
- #3 Design the pages — Waits on #1
- #4 Build the front end — Waits on #3
- #5 Migrate the content — Waits on #2
- #6 Test on real devices — Waits on #4
- #7 Fix what testing found — Waits on #6
- #8 Launch — Waits on #7 · sets the finish date
Days are calendar days, weekends included — same as the workbook. If your team works five days a week, plan the extra days in; the file will not invent them for you.
How the date is worked out
Every task starts on the later of two days: the day the project starts, and the day after the task it waits for finishes. Its finish is that start plus its duration.
That single rule is why a delay travels. Add five days to a task early in the chain and everything behind it slides — the project finish date moves with it, in the same second, without anyone editing a second cell.
The finish date of the project is the latest finish of any task. One task sets it; shortening any other changes nothing. The panel names which one.
What this does not do
A task may only wait for a task above it in the list. That is a real constraint, not an oversight: it is what lets the whole schedule compute in one pass, with no solver and no macro. Most plans are written that way anyway.
It does not resolve a network of dependencies or compute a critical path, and it does not know your calendar. Days are calendar days — weekends and holidays included. If your team works five days a week, plan the extra days in.
And it is arithmetic, not a promise. It assumes the durations you typed are the durations you get.
The spreadsheet, live
This is the file, not a picture of it.
The dashboard below is the example workbook after it calculated — an eighteen-task website relaunch, with the finish date, the slack against the target, and the count of people-weeks over capacity, all worked out by the file itself. Scroll it, select the numbers, check the arithmetic.
| B | C | D | E | F | G | H | I | |
|---|---|---|---|---|---|---|---|---|
| 2 | Project Management Tracker | |||||||
| 3 | Everything below is computed. The only tab you type on is Tasks. | |||||||
| 4 | ||||||||
| 5 | PROJECT FINISHES | DAYS OF SLACK | TASKS LATE | |||||
| 6 | Sep 30, 2026 | -4 | 2 | |||||
| 7 | ||||||||
| 8 | WORK DONE | TASKS, OF WHICH DONE | OVERBOOKED WEEKS | |||||
| 9 | 52.5% | 18 / 8 | 3 | |||||
| 10 | ||||||||
| 11 | ||||||||
| 12 | Where the plan stands | |||||||
| 13 | Status | Tasks | Hours | |||||
| 14 | Not started | 7 | 104 | |||||
| 15 | In progress | 2 | 60 | |||||
| 16 | Blocked | 1 | 6 | |||||
| 17 | Done | 8 | 132 | |||||
| 18 | ||||||||
| 19 | Slack is your target date minus the day the plan actually ends. Negative means the plan does not fit, and Tasks names the one task that sets the date. | |||||||
The spreadsheet this came from
Keep the plan, not just the date.
This page runs the same date arithmetic as the Project Management Tracker, and then forgets it. The workbook keeps it — and adds what a page cannot: a Gantt timeline drawn week by week from the dates it computed, hours by person by week with anything over capacity in red, and a task list that writes its own notes (“Late by 5 days”, “Waiting on #5”). In a file that is yours, works offline, and opens in Excel or Google Sheets.
See the Project Management Tracker — $6.30