Deep Work Planner
Split your available time into optimal Focus and Break blocks using the 90/20 ultradian rhythm. Live countdown timer, energy waveform, and smart distraction handling.
How to use
- 1Choose session type: Deep Work (90/20), Balanced (50/10), or Pomodoro (25/5)
- 2Enter your start time and total available duration
- 3Optional: type the task name you are working on
- 4Press "Start" — the timer counts down using wall-clock accuracy
- 5Hit "Distracted" if interrupted to recover momentum with a shorter sprint
Frequently Asked Questions — Deep Work Planner
Why is 90 minutes the natural limit of deep focus?+
The ultradian rhythm (90 min) governs both sleep and waking states. Within each 90-minute window, the brain depletes glucose reserves and accumulates adenosine — the sleepiness signal. It then needs 15-20 min to recover. Working in these cycles maximizes cognitive output instead of forcing continuous concentration.
How is Deep Work different from Pomodoro?+
Pomodoro (25/5) suits fragmented tasks, studying, or low-energy periods. Deep Work (90/20) is for cognitively demanding work — coding, writing, design — that requires enough uninterrupted time to reach a flow state. Balanced (50/10) is a flexible middle ground.
How does the "Distracted" button work?+
Research shows the brain takes ~23 minutes to return to deep focus after an interruption. Instead of forcing you back into a full 90-min cycle immediately, the tool suggests a 25-minute recovery sprint to re-warm your focus. After that sprint you're primed for a full cycle.
Why drink water during breaks?+
The adult brain is 75% water. Even mild dehydration (1-2%) reduces concentration by 14% and increases fatigue. Drinking 150-200ml during each break maintains steady cognitive performance throughout the session.