The Pomodoro Technique, explained properly

Guides

Work for 25 minutes without interruption, then break for 5. After four rounds, break for 15 to 30. That is the whole method. Everything else is commentary.

Francesco Cirillo named it in the late 1980s after the tomato shaped kitchen timer he used as a student. The mechanism is not the timer though. It is the decision to make the unit of work a fixed length of time rather than a task, because time is something you can finish and a task frequently is not.

The rules that actually matter

1. One block is indivisible. If you break it, it does not count. This is the rule doing the real work, and the one people abandon first.
2. Interruptions get written down, not acted on. Note the thought, return to the block, deal with it in the break.
3. The break is not optional. It is what makes the next block possible.
4. Finish the block even if the task ends early. Use the remainder to review or improve rather than starting something new.
5. Estimate in blocks. Over a week you learn what a task truly costs, which is worth more than the focus itself.

Why 25 minutes

There is nothing sacred about 25. It is long enough to reach something like depth and short enough that starting does not feel like a commitment. That second property is the important one. The technique works because beginning is cheap.

If 25 feels punishing, use 15. A completed 15 minute block beats an abandoned 45 minute one every time, and the number can grow once starting has stopped being the hard part.

Where people go wrong

The two failures are almost always the same. They skip breaks because the work is going well, which borrows from the next hour, and they treat a broken block as a partial success, which quietly removes the only rule with teeth.

Making it survive contact with a real day

Track finished blocks, not intentions. A count of completed focus time is the only honest signal about whether the method is working for you, and it is far more motivating than a to do list, because it goes up.