Enter your wake-up time or bedtime and instantly find the ideal sleep schedule based on 90-minute sleep cycles — so you wake up between cycles feeling alert, not groggy.

We'll calculate the best bedtimes based on 90-min sleep cycles.

Recommended bedtimes

    Sleep cycle timeline (selected option)

    Fall asleep (~14 min)
    90-min cycle

    Sleep Quality Tips

    • 🌙Stick to a schedule: Going to bed and waking at the same time every day — even on weekends — anchors your circadian rhythm.
    • 📵Screen-free wind-down: Avoid bright screens for 30–60 minutes before bed. Blue light suppresses melatonin production.
    • ❄️Cool your room: The ideal sleep temperature is around 65–68°F (18–20°C). A cooler room helps your core body temperature drop, triggering sleep.
    • ☕Cut caffeine early: Caffeine has a half-life of ~5 hours. Stop consuming it at least 6 hours before bedtime for best results.
    • 🛏️Bed = sleep only: Reserve your bed for sleep. Working or watching TV in bed trains your brain to stay alert there.
    • 💡5–6 cycles = optimal: Most adults feel best with 5 or 6 full 90-minute cycles (7.5–9 hours). Waking mid-cycle causes grogginess (sleep inertia).

    Disclaimer: Sleep needs vary by individual age and health. This calculator is for general guidance only and is not medical advice.