Gantt Chart for Sheets™ turns a task list into a project schedule drawn directly into Google Sheets™.

WHAT MAKES IT DIFFERENT

It draws into the sheet, not a sidebar.
Most spreadsheet Gantt tools render inside a sidebar panel. This one writes the chart into a tab of your spreadsheet. That means it keeps working when you have several accounts signed in to the same browser, it works in any modern browser, and the chart is still there when the add-on isn't running — it prints, it shares, and it survives.

No row cap. No project-length cap.
Chart 50 tasks on the free plan or unlimited tasks on Pro. Either way there is no limit on how long the project runs: the timeline automatically switches between day, week, month and quarter scales, so a two-week sprint and a five-year programme both fit on one screen.

Nothing ever disappears silently.
If a row can't be placed on the chart, it is listed underneath it with the reason — "needs a start date", "ends before it starts", "part of a circular dependency". You are never left wondering why a task vanished.

Start with the format the add-on provides.
Choose **Create task template** in the add-on menu for the basic task list, or open **Gantt tools** for simple, team-workload, and plan-vs-actual starter tabs. Each template contains editable examples without changing your existing sheet. Edit a template, then choose **Build Gantt chart**. If you choose Build on a sheet without the required columns, the add-on offers to create the basic template for you. The complete workflow stays in Google Sheets™.

Use the task sheet you already have—without rearranging columns.
Your table doesn't have to start at cell A1. Column headings are recognised automatically in English, Korean, Japanese, Spanish, Portuguese, French and German, and unfamiliar columns can be inferred from their contents. The interface follows the account language in English, Korean, Japanese, Spanish, Brazilian Portuguese or German, with English as the fallback. If a guess needs correction, choose **Connect and preview task sheet** in **Gantt tools**. Map the task name, planned dates or duration, owner, progress, predecessors, WBS fields, effort and capacity to their source columns. The preview shows the first six parsed tasks, schedule-adjusted dates, and counts for missing-start and unscheduled tasks before you save. The choice is remembered for that task tab; **Not used** prevents a field from being guessed. Dates are read as ISO, dd/mm/yyyy, mm/dd/yyyy or native spreadsheet date values, with the day/month order inferred from your data and the account locale used only when the sheet is ambiguous. The task sheet is not reformatted or rewritten. Excel workbooks must first be opened as Google Sheets™ copies because Marketplace add-ons do not run in Office editing mode; conversion leaves the Excel original unchanged.

WHO IS DOUBLE-BOOKED

Name an owner on each task and the chart shows how many tasks each person carries, how many days they are busy, and the stretches where someone is double-booked.

Add **Total effort hours** to divide a task's hours evenly among its owners and scheduled working days. Or enter **Hours per day** directly for each assignee; that value takes precedence over the total. Daily capacity defaults to eight hours and can be entered in the sheet. Days above capacity are highlighted on the timeline and listed with the task names. Tasks without an hours value are clearly excluded instead of receiving an invented estimate.

PROJECT PULSE

Add a Progress column to compare actual completion with the work planned by today's date. The chart summarizes the gap and calls out unfinished late tasks and work that is falling behind. The calculation stays in the spreadsheet.

SCHEDULING

• Dependencies — finish-to-start links with lag or lead ("12", "12+3", "12-1"). Dates are calculated from the chain, so you set one start date and the rest follow.
• WBS rollup — outline levels or a parent column group tasks into phases. Summary bars span their children automatically, and summary progress is weighted by duration, so a ten-day task at 50% counts for more than a one-day task at 100%.
• Critical path — a full forward and backward pass marks the tasks with no float, and reports the slack on everything else.
• Working days — skip weekends and your own holiday list. Slack is then measured in working days too, not calendar days.
• Circular dependencies are detected and named instead of hanging.
• Predecessor labels in whichever form you read fastest: id, task name, or "id - task name".

WHAT IT LOOKS LIKE

Summary bars, task bars, completed portions, milestones and critical-path tasks each get their own colour. Weekends are shaded. Phases are indented. Freeze panes are set for you so the task names stay put as you scroll the timeline.

PERMISSIONS

This add-on asks for two permissions, and both are the narrowest available:
• See and edit only the spreadsheet you are using it in — not your other files or folders.
• Show a menu and dialogs.

That is the whole list. It cannot open your other spreadsheets, it cannot run while you are away, and it has no permission to access the internet — so nothing you put in your spreadsheet can leave it. Your schedule is computed on your own machine, inside your own document.

The install screen also asks for your name and email address. Every add-on installed from the Marketplace requests those; it is Google identifying who is installing, not us. The add-on never reads them and we never receive them.

If you are an administrator deciding whether to allow this for a domain, that short scope list is the point.

FREE AND PRO

Free — up to 50 tasks, unlimited project length, full colours, dependency scheduling, WBS rollup, critical path, working-day calendars, workload conflict detection.
Pro — unlimited tasks, dependency labels, custom chart colours, no watermark. Current pricing and terms are at slowgrain.app/gantt-for-sheets; one licence key applies to every spreadsheet you open.

GETTING STARTED

1. Open the **Gantt Chart for Sheets™** menu and choose **Create task template**, open **Gantt tools** for a team or plan-vs-actual template, or use your own task list.
2. Enter a task name, start date, and either duration or end date. Use the After column for an earlier task ID when needed.
3. Choose **Build Gantt chart**. A "Gantt" tab appears with your chart; the source task sheet is not modified.

Re-run it any time your plan changes; the chart is rebuilt from scratch.

Google Sheets™ is a trademark of Google LLC. Google LLC does not sponsor or approve this add-on.