25/5 vs 50/10 vs 52/17 vs 90 Minutes
pomofox · October 2, 2026
There are four focus rhythms people actually use: the classic 25/5 pomodoro timer, the 50/10 class hour, the 52/17 ratio from DeskTime's data, and the 90 minute deep work block. They are all the same idea, focus then rest, at different sizes.
This is a side-by-side comparison and a quick way to pick one. For the method underneath all four, see the pomodoro technique.
The four rhythms side by side
| 25 / 5 | 50 / 10 | 52 / 17 | 90 / 15 | |
|---|---|---|---|---|
| Focus blocks in 4 hours | about 8 | 4 | about 3 to 4 | 2 to 3 |
| Breaks per hour | 2 | 1 | about 1 | under 1 |
| Origin | Cirillo, 1980s | the school period | DeskTime data, 2014 | ultradian rhythm, deep work |
| Strength | easy to start, robust to interruptions | clock-aligned, enough warm-up | long, restorative breaks | real flow on big tasks |
| Weakness | bell can break flow | 50 minutes is hard on low days | 17 minutes is a lot of rest to manage | needs a clear calendar and stamina |
| Timer | pomodoro timer | 50/10 timer | 52/17 timer | deep work timer |
Choose by the kind of work
- Memorizing, flashcards, quick review: 25/5. Recall gets sloppy before attention does, and short rounds keep it sharp.
- Problem sets, reading with notes: 50/10. Enough time to get into a problem, a clean break every hour.
- Writing, design, analysis: 52/17 or 90/15. These have the longest warm-up and benefit most from long blocks.
- Admin, email, chores: 25/5, or batch them into one pomodoro and be done.
Choose by your day
Your calendar matters as much as the task. A morning with nothing in it can hold two 90 minute blocks. An afternoon broken up by calls cannot, and forcing 50 minute blocks into 40 minute gaps just means abandoning them. On fragmented days, fit single 25 minute timer blocks into the gaps instead.
Energy is the other variable. Long blocks are a good-day tool. On a tired day, dropping to 25/5, or even 15/5, keeps you moving without the feeling of failing a bigger session.
A one-week experiment
If you cannot decide, test. Spend two days on 25/5, two on 50/10 and one on 90/15, on similar work. At the end of each day, write down two numbers: how many blocks you finished, and how much of the task actually got done. The rhythm that wins on the second number, not the first, is yours.
What do people actually choose? In pomofox's focus sessions data report, 25 minutes accounts for over half of all sessions, 30 minutes for about one in ten, and 50 minutes for about one in twelve.
Frequently asked questions
Which is better, 25/5 or 50/10?
25/5 suits short tasks, memorizing and interrupted days. 50/10 suits problem sets, reading and writing. Pick by the task.
Is 52/17 backed by research?
It comes from DeskTime's 2014 analysis of its most productive users. It describes what those people did; it does not prove that the ratio causes productivity.
Related
- pomodoro technique the method behind every rhythm.
- 50/10 timer the class-hour rhythm.
- 52/17 timer work 52, rest 17.
- 90 minute timer one full ultradian block.