Construction Schedule Calculator
Estimate a construction schedule from task durations and dependencies: total project duration, finish date, critical path and float for every task (CPM).
Input
One task per line: "Name, working days, predecessors". Predecessors are task numbers or names separated by ";" (leave blank for none). Lines starting with # are ignored.
Adds calendar start and finish dates. Leave blank to see working-day numbers only.
Which days count as working days when a start date is set. Holidays are not modelled.
Output
Tasks with zero float, in schedule order. A delay to any of them delays the whole project.
| # | Task | Days | Start | Finish | Float | Critical |
|---|---|---|---|---|---|---|
| No data yet | ||||||
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/construction-schedule-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"tasks": "Site clearing, 3\nExcavation, 5, 1\nFoundations, 1…",
"startDate": "2026-01-05",
"workWeek": "5"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `construction-schedule-calculator` tool (Construction Schedule Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/construction-schedule-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="Construction Schedule Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
The Construction Schedule Calculator turns a list of tasks, durations and dependencies into a project schedule using the Critical Path Method (CPM). Paste your task list and it returns the total duration, the finish date, every task's start and finish, how much each can slip (float), and the critical path — the chain of tasks that sets the end date.
How to use it
- Enter one task per line as
Name, working days, predecessors. Predecessors are task numbers (line order) or task names, separated by;. Leave blank when a task can start immediately. - Optionally pick a start date and work week (5, 6 or 7 days) to get calendar dates.
- Read the summary, the critical path and the per-task table. Download the table as CSV.
Example: External works, 7, Underground services; Structure starts only when both predecessors have finished.
What the columns mean
- Start / Finish — the earliest dates each task can run, based on its predecessors.
- Float — working days a task can slip without delaying the project. Zero float means the task is critical.
- Critical — tasks with no float. Any delay to them delays the whole job.
Notes and limits
All dependencies are finish-to-start with no lag. Holidays are not modelled; durations are whole working days (use 0 for a milestone). Circular dependencies are reported as an error. Everything runs in your browser, so your task list is never uploaded.