25 minutes on, 5 off? Or 52 and 17? Or long 90-minute blocks? If you've ever googled "best study method", you've met all three. Here's what each one is, where it comes from, how much real evidence is behind it, and how to find the one that fits you.
The short answer
- 25/5 if starting is your problem, you get distracted easily, or you're studying something you don't love.
- 52/17 if you like a bit more depth but still want proper breaks.
- 90/20 if you're already in flow easily and have long, uninterrupted time (writing, projects, coding).
Over three hours, the difference in pure focus time is small: roughly 140, 146 and 160 minutes. What matters more is which rhythm you can actually keep.
1. 25/5: short sprints
The classic 25-minute block comes from the Pomodoro Technique®, created by Francesco Cirillo in the late 1980s with a tomato-shaped kitchen timer. You work 25 minutes on one task, break for 5, and take a longer 15 to 30 minute break after four rounds. (Here's the full story.)
Good for: getting started, revision, homework, subjects you'd rather avoid, days with low energy.
Less good for: tasks where you need 15 minutes just to warm up, like writing an essay.
Try it: free 25-minute timer
2. 52/17: the "office data" rhythm
In 2014, the time-tracking company DeskTime looked at its most productive users and found they worked about 52 minutes and then broke for about 17. It became a famous rule. Fun twist: when DeskTime repeated the analysis in 2021, the top users' rhythm had shifted to around 112 minutes on and 26 off.
Honest note: this is data from office workers using one app, not a study on students, and it shows a pattern, not a cause. Still, it's a useful middle ground.
Good for: reading, problem sets, longer tasks.
Less good for: very tired days, or if 17-minute breaks turn into an hour of scrolling.
Try it: free 52/17 timer or the simpler 50/10 study timer
3. 90/20: deep work blocks
The 90-minute idea goes back to sleep researcher Nathan Kleitman, who described roughly 90-minute cycles in sleep and suggested a similar "rest-activity" rhythm during the day. It was popularised by research on expert performance: top violinists in a well-known study by Anders Ericsson practised in sessions of up to about 90 minutes, with breaks in between.
Honest note: the evidence for a fixed 90-minute rhythm while awake is much weaker than for sleep. Think of 90 minutes as an upper limit for deep focus, not a magic number.
Good for: essays, projects, coding, practising an instrument.
Less good for: beginners, or when you keep checking your phone after 20 minutes.
Try it: free 90-minute focus timer
Free: Koa's Focus Cheat Sheet
The cycle, Koa's 5 rules, break ideas and a daily tracker on one printable page.
How to find your rhythm in one week
- Days 1 and 2: 25/5. Count how many blocks you finish.
- Days 3 and 4: 50/10 (close enough to 52/17 and easier to set).
- Day 5: one 90-minute block for your hardest task.
- Weekend: look back. Where did you get the most done, and where did you feel least drained? That's your rhythm.
You can mix, too: 90 minutes for the essay in the morning, 25/5 for vocabulary in the evening.
Whatever you pick: protect the break
A 2022 review of 22 studies found that short breaks (10 minutes or less) go together with more energy and less fatigue. The break only works if it's a real break: stand up, drink water, look out of the window. Not your phone.
Which timer app should you use for this? We compared seven free study timers (prices, accounts, ads) in Best free study timers in 2026 (no account needed).
Try it with Koa
The free Koa study timer lets you set any focus and break length, so you can test all three rhythms this week. One click sets it up: 25/5 · 50/10 · 52/17 · 90/20. No account, no ads, and Koa naps on your breaks.
Shade of the day: Thulian
Today's shade is no. 18, Thulian (#DE6FA1), a rosy pink with a hint of purple. It pairs with turquoise, lilac and mint, and it's a great colour for the sticky note that says "only 25 minutes".
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Sources: DeskTime: the 52/17 rule and the 2021 update · Fast Company on 90-minute cycles (Kleitman, Ericsson) · Albulescu et al., PLOS ONE 2022.
Pomodoro® and Pomodoro Technique® are registered trademarks of Francesco Cirillo. Pinkoa is not affiliated with, associated with or endorsed by the Pomodoro Technique® or Francesco Cirillo.