Wake up refreshed — find the best sleep and wake times based on your natural 90-minute sleep cycles.
Sleep is not a single continuous state. Your brain cycles through distinct stages roughly every 90 minutes — light sleep (N1, N2), deep slow-wave sleep (N3), and REM (Rapid Eye Movement) sleep. Together, these form one complete sleep cycle.
Waking up mid-cycle — especially during deep sleep — is what causes that groggy, disoriented feeling known as sleep inertia. Waking up at the natural end of a cycle, when sleep is lightest, leaves you feeling alert and rested even if total sleep time is the same.
This calculator works backwards from your desired wake-up time in 90-minute intervals to give you the ideal bedtimes. Similarly, it calculates forward from your bedtime to show the best wake-up windows.
Blue light from screens suppresses melatonin production by up to 50%. Enable Night Mode or put the phone in another room 30 minutes before sleep.
Core body temperature drops during sleep. A room at 20–23°C promotes faster sleep onset. In Indian summers, use a fan or AC on a timer rather than keeping it off.
Caffeine has a half-life of 5–6 hours. An afternoon chai at 4 PM still has 50% of its caffeine at 10 PM. Switch to herbal tea or warm milk in evenings.
Your circadian rhythm is a biological clock. Going to sleep and waking at the same time daily — even on weekends — is the single most impactful sleep habit you can build.
Eating a heavy Indian dinner after 9 PM raises body temperature and forces digestion during sleep, reducing deep sleep quality. Aim to finish dinner 2–3 hours before bed.
Inhale for 4 counts, hold for 7, exhale for 8. This activates the parasympathetic nervous system and can reduce the time to fall asleep significantly within 2–3 weeks of practice.