Track project timelines, dependencies, and milestones with our comprehensive Gantt chart template
✓ Free to download · ✓ Excel 2016+ and Google Sheets · ✓ Custom version in 24h
A Gantt chart drawn with coloured cells is a picture. This one derives the bars from start dates, durations and predecessors, so moving one task moves everything that depends on it.
The actual columns, with sample rows
| A | B | C | D | E | F | G |
|---|---|---|---|---|---|---|
| 1 | Task | Pred. | Start | Days | End | Slack |
| 2 | Discovery | — | 2026-09-01 | 10 | 2026-09-12 | 0 |
| 3 | Design | 1 | 2026-09-15 | 15 | 2026-10-03 | 0 |
| 4 | Build | 2 | 2026-10-06 | 30 | 2026-11-14 | 0 |
| 5 | Content | 1 | 2026-09-15 | 20 | 2026-10-10 | 18 |
Why each one is written the way it is
=IF([@Pred.]="—", ProjectStart, WORKDAY(INDEX(Tasks[End],[@Pred.]),1,Holidays))
Start date from the predecessor's end, skipping weekends and holidays. This is what makes the chart a model rather than a drawing.
=WORKDAY([@Start],[@Days]-1,Holidays)
End date in working days. Using calendar days is the reason most hand-built Ganttes are optimistic by about 40%.
=NETWORKDAYS([@End], LatestFinish, Holidays)
Slack: how far a task can slip without moving the project. Tasks with zero slack are the critical path, and they are the only ones worth escalating.
=IF(AND(ColDate>=[@Start],ColDate<=[@End]),"█","")
The bar itself, as conditional formatting across a date row. It is a rendering of the dates, never a source of them.
A worked example with real numbers
A website project ran two tasks late in the same week and the team escalated both. The slack column showed content had 18 days of float while design had none — the design slip pushed the launch, the content slip cost nothing. Escalating only the critical-path task saved a week of unnecessary weekend work on the other.
Tab by tab
| Tab | Contents |
|---|---|
| Tasks | Task, predecessor, duration, owner and percentage complete. |
| Chart | The Gantt rendering across a date axis. |
| Holidays | Non-working days feeding every date calculation. |
| Critical path | Tasks with zero slack, listed. |
| README | How predecessors are referenced and how to add a task. |
What is included, and what to look at next
Specific to this workbook, not generic
The template models finish-to-start with a single predecessor, which covers most projects. Multiple predecessors need a MAX over their end dates — a small change we are happy to make as a custom build.
Because a 10-day task starting Friday finishes in two weeks, not on the following Monday. Calendar-day Ganttes are systematically optimistic.
How long a task can be late before the project end moves. Zero slack means it is on the critical path; a task with 18 days of float being late is not news.
"This Gantt chart template has revolutionized our project planning. The visual timeline and dependency tracking have helped us deliver projects on time consistently."