November 12, 2026 · EdTech · 9 min read

How to Make a School Timetable Automatically (Free vs AI Tools)

Building a clash-free timetable by hand can take days. Here is how to do it automatically, what to prepare first, and an honest comparison of free tools, paid software and AI timetable generators.

Why school timetables are so hard to make by hand

A timetable looks like a simple grid, but every cell has to satisfy rules at the same time. One teacher can't be in two classes at once, the science lab can only hold one group, and each subject needs its weekly periods.

Add part-time teachers, double periods, and teachers who are only free on certain days, and the number of possible combinations grows very quickly. That is exactly the kind of problem software is good at.

These rules are called constraints. Every automatic tool, free or paid, works the same way at heart: you describe your constraints, and it searches for a timetable that breaks none of the hard ones and as few of the soft ones as possible.

Before you use any tool: collect your data

This is the step that decides whether automatic generation works. Most failed timetables come from missing or wrong data, not from the software. Gather this first:

• School week: working days, periods per day, break times and period lengths.
• Classes and sections: for example Grade 6-A, 6-B, 7-A.
• Subjects per class and how many periods each needs per week.
• Teachers: which subjects and classes each one teaches, and their maximum periods per day or week.
• Teacher availability: days or periods a teacher can't work (part-timers, shared staff).
• Rooms: labs, computer rooms and any subject that needs a specific room.
• Special rules: double periods, subjects that shouldn't fall in the last period, or two sections taught together.

Put it all in one spreadsheet. Whichever tool you choose, you will be typing or importing from this list.

Your options at a glance

Details checked against each tool's official site or listing in November 2026. Features and prices change, so confirm on the official site before deciding.

Option 1: A spreadsheet (free, but manual)

Many schools still build timetables in Excel or Google Sheets. It costs nothing and everyone knows how to use it. You can add conditional formatting to highlight a teacher's name appearing twice in the same period.

The problem is that you are still the solver. Every change can break three other cells, and checking for clashes is up to you. For more than a handful of teachers, it is usually the slowest free option, not the cheapest.

Option 2: FET (free, open-source software)

FET is free, open-source timetabling software for schools and universities. It runs on Windows, macOS and Linux, has a fully automatic generation algorithm, and can export timetables to HTML, XML and CSV. It is actively maintained; version 7.10.3 was released in September 2026.

FET is genuinely powerful and supports a very wide range of constraints. The trade-off is the learning curve: the interface is dense, and it takes time to enter data and understand why a timetable can't be generated. If your school has a patient, technical person to own the timetable, FET is hard to beat on price.

Option 3: aSc TimeTables (paid, with a free trial)

aSc TimeTables is a long-established commercial timetabling package. It runs online with no installation, or as a Windows application that works offline. Its free trial has no time limit and can do everything the paid version can, except export, and printouts carry a watermark.

Beyond generation, it includes features like substitution management and sharing timetables with teachers, students and parents. It suits schools that want a mature, full-featured product and have the budget for a license.

Option 4: General AI chatbots

You can paste your teachers and subjects into a general AI chatbot and ask for a timetable. For a tiny school or a single class, this can give you a useful first draft in seconds.

For a full school, be careful. A chatbot generates text that looks like a timetable; it is not a dedicated solver that guarantees every constraint. Always check the result for teacher and room clashes before you rely on it, and expect to redo it whenever something changes.

Option 5: AI timetable platforms like Academic Scheduler

This is the category I work in. Academic Scheduler is a web-based timetable generator built for schools, colleges and other institutions. You add your teachers, subjects, classes, periods and constraints, and it generates the timetable for you.

• Automatic, AI-assisted generation from your teachers, classes, subjects and periods.
• Real-time conflict detection that flags teacher, room and class clashes as you work.
• Class and teacher views so each person sees their own schedule.
• Substitution management for when a teacher is absent.
• Export to PDF, Excel or CSV for printing and sharing.

Because it runs in the browser, there is nothing to install, and more than one person can work on the timetable. It won't suit every school, and if you need a very specialised constraint, compare it against FET and aSc before deciding.

How to make a school timetable automatically, step by step

The exact screens differ between tools, but the workflow is almost the same in all of them:

1. Set up the school week: days, periods per day and breaks.
2. Add classes, subjects and teachers from your data spreadsheet (import if the tool supports it).
3. Create the lessons: which teacher teaches which subject to which class, and how many periods a week.
4. Add constraints: teacher unavailability, rooms, double periods and daily limits. Start with hard rules only.
5. Generate the timetable. If it fails, the tool will usually point to the rule that can't be met.
6. Review and adjust by hand, then add soft preferences one at a time and regenerate.
7. Publish and share class and teacher timetables as PDF, Excel or an online link.

A tip from experience: add constraints gradually. If you enter fifty rules at once and generation fails, it is hard to find which one is impossible. Get a basic valid timetable first, then tighten it.

Which option should you choose?

• A small school with a few teachers: a spreadsheet or a general AI draft may be enough, as long as you check for clashes.
• No budget and someone technical on staff: FET is free and very capable.
• A large school wanting an established desktop-and-online package: try the aSc TimeTables free trial with your real data.
• A school wanting a simple browser-based workflow with conflict checks and exports: try an online AI platform such as Academic Scheduler.

Whatever you choose, test it with your real data, not a demo. The best tool is the one your timetabler can actually use every term.

Frequently asked questions

Is there free software to make a school timetable?

Yes. FET is free, open-source timetabling software that runs on Windows, macOS and Linux and can generate timetables automatically. Spreadsheets are also free but require you to build and check the timetable by hand.

Can AI make a school timetable?

Yes, but the type of AI matters. Dedicated timetable tools combine automatic generation with clash checks. General chatbots can draft a simple timetable, but you need to verify it carefully for teacher and room conflicts.

Can ChatGPT make a timetable for my school?

A general chatbot can produce a draft for a small number of classes. For a whole school with many teachers and rules, use a dedicated tool or check every period yourself, because a chatbot does not guarantee a clash-free result.

How long does it take to generate a timetable automatically?

Generation itself often takes minutes. Most of the time goes into collecting and entering accurate data, and into fixing constraints that turn out to be impossible.

What information do I need before making a timetable?

You need your working days and periods, classes and sections, subjects with periods per week, which teacher teaches what, teacher availability, rooms, and any special rules like double periods.

What happens when a teacher is absent?

Some tools, including aSc TimeTables and Academic Scheduler, include substitution management to help you find a free teacher for the missed periods. With a spreadsheet, you have to find a free teacher manually.

An automatic timetable is only as good as the data you give it. Spend an afternoon getting your teachers, subjects and rules right, pick the tool that fits your school, and let the software handle the clashes. If you try Academic Scheduler and something doesn't fit your school's rules, I would genuinely like to hear about it.