# Critical path and slack

The critical path consists of tasks whose delay would delay the project’s end, shown in red on the Gantt diagram. It displays the float alongside other tasks.

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## Steps

- Open the project's Gantt tab.

- Ensure the Critical Path box at the top is checked 1.

- Red bars and arrows indicate the critical path 2; +N next to the task name indicates the slack of that task.

## What is float?

Slack is the number of working days a task can be delayed without delaying the project's completion. Tasks with no slack are on the critical path. Calculation is done by tracing dependencies backwards from the project's latest-finishing task.

> Tip: Shortening or parallelising a task on the critical path brings the project end date forward; speeding up a task with slack does not change the end date.

## Related pages

- How auto-scroll works

- Adding milestones