- Home
- Study and Work Timers
- Deep Work Timer
Deep Work Timer
Write down one demanding task, press Start and give it 90 uninterrupted minutes. A 20-minute break follows, then a second block.
Session 1 of 2
Deep work session lengths
| Preset | Focus | Break | Before the 30-min break | Suits |
|---|---|---|---|---|
| 60 / 15 | 60 min | 15 min | 3 blocks (3 h of focus) | Your first weeks, or a day with meetings around it |
| 90 / 20 | 90 min | 20 min | 2 blocks (3 h of focus) | Writing, programming, analysis, exam-level study |
| 120 / 30 | 120 min | 30 min | 2 blocks (4 h of focus) | Practiced deep workers with a clear morning |
A sample morning on the default: 8:30–10:00 first block, break until 10:20, second block 10:20–11:50, then the 30-minute break. These lengths are common practice, not measured limits.
How to use it
- Before you start, decide the task and the finish line: “outline chapters 3 and 4”, not “work on the book”. Type it in the box at the top.
- Put your phone in another room and close mail and chat. Keep only the windows the task needs.
- Press Start. The focus phase runs 90 minutes, then the timer rings and the 20-minute break begins.
- After the second block the break is 30 minutes. Before you leave the desk, write a shutdown note: where you stopped and the next step.
What deep work means
“Deep work” is the term popularized by Cal Newport’s 2016 book of that name. It describes distraction-free concentration on a cognitively demanding task: the proof, the architecture decision, the difficult chapter. Its opposite is shallow work such as email, scheduling and routine updates, which you can do while half-distracted.
Newport suggests that most people can manage at most about four hours of deep work a day, and that beginners manage far less, about an hour. That is why the default here stops at two 90-minute blocks. Three focused hours before lunch is a strong day; the afternoon can go to shallow work.
Why 90 minutes
The 90-minute work cycle echoes the roughly 90-minute cycles that sleep researcher Nathaniel Kleitman described, which are often called ultradian rhythms. Treat the link to daytime work as a popular rule of thumb, not an established fact. The practical argument is plainer: hard problems take 15 to 20 minutes to load into your head, so a short block ends as you become useful, and few people hold full concentration much beyond an hour and a half.
The rituals around the block do as much as its length. Decide the task the evening before so the session opens with work, not with planning. Use the same place and the same starting time. End with the shutdown note so the unfinished problem is on paper and you can stop thinking about it during the break.
Common mistakes
- Starting at 120 minutes. If you are new to this, use 60 / 15 for a couple of weeks and lengthen the block when an hour feels short.
- Sitting down without a defined task. The first 20 minutes disappear into choosing what to do.
- Counting a block that included “a quick look” at messages. One glance leaves part of your attention on the message for several minutes afterwards.
- Spending the 20-minute break on news or social feeds. Walk, eat, look out of a window; let the problem settle.
- Scheduling deep work for the slump after lunch. Put it where your energy is highest, which for most people is the morning.
Questions people ask
How long should a deep work session be?
Sixty to 90 minutes suits most people, and 90 is the usual choice once you are practiced. Beginners often do better with one 60-minute block a day and build from there.
How many hours of deep work can you do in a day?
Cal Newport puts the ceiling at about four hours for most people, with beginners nearer one hour. Two 90-minute blocks give three hours; the 120 / 30 preset run twice gives four.
Is the 90-minute ultradian rhythm real?
Nathaniel Kleitman described roughly 90-minute cycles in sleep and proposed that a similar rest-activity cycle continues through the day. Whether it governs concentration at a desk is not settled, so use 90 minutes as a convenient block length and adjust to what you observe in yourself.
What should I do in the break between deep work sessions?
Leave the screen. Walk, stretch, have a drink or a snack. Avoid email: it restarts the shallow thinking the block was meant to shut out.
How is this different from a Pomodoro timer?
The mechanism is the same, focus then break, but a Pomodoro is 25 minutes and a deep work block is 60 to 120. Short cycles help you start; long blocks let you stay inside one hard problem.