A pomodoro interval is the work-to-break ratio you run. The classic is 25/5, but 50/10, 52/17, 90/20, 45/15, 40/20 and even 15/3 all work, and the right one depends on how long your work takes to get going. If the timer regularly cuts you off mid-thought, your interval is too short. If you never reach the bell, it’s too long.
The seven ratios
| Ratio | Work | Break | Four sessions take | Suits |
|---|---|---|---|---|
| 25/5 | 25 | 5 | 1 hour 55 minutes | Starting trouble, study, admin |
| 50/10 | 50 | 10 | 3 hours 50 minutes | Writing, coding, problem sets |
| 52/17 | 52 | 17 | 4 hours 19 minutes | Full days where breaks matter |
| 90/20 | 90 | 20 | 5 hours 10 minutes (3 sessions) | Deep work, long warm-up |
| 45/15 | 45 | 15 | 3 hours 45 minutes | Lectures, revision, timed papers |
| 40/20 | 40 | ~20 | 3 hours 40 minutes | Break as a reward |
| 15/3 | 15 | 3 | 1 hour 9 minutes | Dread, ADHD, restarting a habit |
Start each one straight away: 25/5, 50/10, 52/17, 90/20, 45/15, 40/20, 15/3. Or set your own on the custom timer.
Is 25/5 or 50/10 better?
Neither, and the honest answer turns on one question: how long does your work take to get going?
Some tasks start instantly. Flashcards, email, data entry, reading something straightforward. You’re at full speed within a minute, so 25 minutes gives you roughly 24 useful minutes and the ratio is efficient.
Other tasks have a warm-up. Debugging unfamiliar code, restructuring an argument, a maths problem you haven’t seen before. You spend ten to fifteen minutes rebuilding the state of the problem in your head before you’re any good at it. On that work, a 25-minute session gives you ten useful minutes and then throws away the setup. Run it four times and you’ve paid the warm-up four times.
So: fast-start work, use 25/5. Slow-start work, use 50/10 or longer. Most people do both kinds in a day and should switch ratios rather than pick a favourite.
There’s a second question underneath it, which is whether your problem is starting or stopping. Short intervals help you start. Long intervals stop you being interrupted. They don’t solve each other’s problem, and picking the wrong one makes things worse, not neutral.
What the ratios are actually for
25/5 is the original, from Francesco Cirillo in the late 1980s. Its real strength is that 25 minutes is a small enough ask that you’ll agree to it on a bad day.
50/10 is the default upgrade. Keeps the 5:1 work-to-break proportion, doubles the unit. Nothing clever, and it fixes most complaints about 25 minutes.
52/17 comes from data rather than design. DeskTime looked at the most productive 10% of users of its time-tracking software in 2014 and found they averaged 52 minutes of work and 17 of break. The long break is the part people skip and the part that matters: 17 minutes is enough to leave the building.
90/20 lines up with the ultradian rhythm argument, though the evidence for a 90-minute cognitive cycle is thinner than it’s usually presented. Use it because your work has a long warm-up, not because of biology.
45/15 maps onto how education is already structured. If you’re used to 45-minute lectures or 45-minute exam sections, your attention is already shaped to it. Handy for timed past papers.
40/20 is the animedoro shape: work long enough to get somewhere, then take a break big enough to want. One anime episode is about 20 minutes without credits.
15/3 is for when nothing else is working. If the task is one you’re dreading, or you’ve fallen off the habit entirely, 15 minutes gets you past the part where starting is the whole battle. Use the 15-minute timer and stop apologising for it.
Picking one this week
Try this rather than theorising. Run your normal work at 25/5 for two days and note, each time the timer rings, whether you were mid-flow or relieved.
Mid-flow most times, move up to 50/10. Relieved most times, either the interval is too long or the task is too vague, and it’s usually the task.
Then leave it alone for a week. Switching ratios daily means you’re never measuring anything.
Two things that matter more than the ratio
The break has to be a break. A 10-minute break spent reading a screen isn’t rest for a brain that’s been reading a screen. Stand up, walk somewhere. This matters more than whether your break is 10 minutes or 17.
The task has to be definable. If you can’t say what the next session is for in a short phrase, no ratio saves it. You’ll spend the first eight minutes deciding, which is exactly the failure the timer was supposed to prevent.
FAQ
What is the best pomodoro interval?
The one that matches how long your work takes to get going. Fast-start work (flashcards, email, reading) does well at 25/5. Slow-start work (debugging, complex writing, maths) does better at 50/10 or 90/20. Most people need two ratios, not one.
Is 50/10 better than 25/5?
Better for work with a warm-up cost, worse if your problem is starting at all. A 50-minute commitment is harder to agree to on a day you’re avoiding the task, and a 50-minute session you abandon at minute 12 is worth less than a 25-minute one you finish.
How long should the long break be?
Between 15 and 30 minutes after four work sessions, and long enough to leave your desk and eat something. Cirillo’s published range is 20 to 30 minutes. Most timers default to 15, which is workable but on the short side for a full day.
Can I change the pomodoro interval to anything I want?
Yes. The ratio is not the method; single-tasking and a real break are. Set any work and break length on the custom timer, from a 1-minute sprint to a 2-hour block, and keep the rest of the structure.
What ratio works for ADHD?
Often something shorter than 25 minutes to begin with, because the hard part is starting rather than sustaining. Many people do well at 10 or 15 minutes and build up. See pomodoro technique for ADHD for the detail.
Pick the one that fits your work and start now: 25/5 if starting is the problem, 50/10 if the bell keeps cutting you off.