Project delay impact calculator

A task slipped. Does the deadline move? Pick a task below and see what it costs — worked out by a real critical-path engine, not a rule of thumb.
By how long?

Completion slips to 2 Jun 2026 — 10 days late.

Site survey & measure is on the critical path — zero float — so every day it slips is a day the whole project slips. 14 downstream tasks move with it.

Office fit-out — Level 4Baseline finish 23 May 2026
  1. critical
  2. critical
  3. critical
  4. critical
  5. critical
  6. critical
  7. critical
  8. 42 d float
  9. 34 d float
  10. 34 d float
  11. 41 d float
  12. 41 d float
  13. 66 d float
  14. 66 d float
  15. 7 d float
Baseline+10d

Every figure here is computed by the same critical-path engine GanttPilot runs on real plans — solved ahead of time for this fixed example, not estimated in the browser.

Why the answer is not always “ten days late”

A ten-day slip does not cost ten days. It costs whatever is left after the task's float is spent. Some tasks have weeks of slack and absorb the whole thing without touching the deadline. Some have none, and every day they lose the project loses too.

The interesting case is the one in between: a task with a week of float that slips ten days. The first seven days cost nothing and the last three cost you the deadline. That is the number nobody can work out in their head, and the one a spreadsheet will never tell you, because a spreadsheet does not know which task feeds which.

How to read your own plan this way

Float is only meaningful if your tasks are actually linked. A schedule of dates with no dependencies between them has no critical path and no float to report — every task looks independent, so nothing appears to knock anything else. That is why an exported date list often looks fine right up until the day it does not.

Import a plan you already have and GanttPilot works out the links, the critical path and the float for you, then answers this same question about your own tasks — including the ones where the honest answer is “that one is fine, stop worrying about it”.

Open a live sample plan — no signup