Sleep Calculator: Bedtime

PREMIUM — PURCHASE REQUIRED: All features described below are part of Pro and require a purchase: a weekly or yearly auto-renewing subscription, or a one-time lifetime purchase. What time should you go to bed tonight? Enter the time you need to wake up, and this sleep calculator answers in seconds — four bedtimes that each land on the boundary of a 90-minute sleep cycle, so your alarm catches you between cycles instead of dragging you out of deep sleep feeling groggy. No sensor, no wearable, no phone under your pillow. This is honest arithmetic done entirely on your device: whole 90-minute cycles plus the 14-minute average an adult needs to fall asleep, the population figures reported by the Sleep Foundation. The app never claims to measure your sleep — it helps you time it. WHAT YOU GET • Type in a 6:30 AM wake-up and get bedtimes for 6, 5, 4 or 3 full cycles — the Ideal one marked, each with its exact hours of sleep • Flip the switch and go the other way: pick your bedtime and see the best times to set your alarm • "If you sleep now" — three cycle-aligned wake times counted from this exact minute, for nights you're already late • A nap calculator with the four naps worth taking: 20-minute power nap, 30-minute recovery, 60-minute memory nap, full 90-minute cycle — each schedules a wake reminder • Repeating wake reminders for weekdays, weekends or any day pattern, with an optional gentle nudge a few minutes early • Eight synthesized sleep sounds — night rain, ocean waves, white and brown noise, forest night — that mix together and keep playing in the background, plus a wind-down timer with a guided 4-7-8 breathing pace PERFECT FOR • Shift workers whose bedtime changes every week and need the math done for them • Students timing all-nighters and power naps around classes • New parents grabbing sleep in whatever window the baby allows • Anyone who sleeps 8 hours yet still wakes up groggy — the problem is usually where the alarm lands, not how long you slept WHY NOT JUST A SLEEP TRACKER? Trackers ask you to wear a watch to bed or leave your phone recording on the mattress all night, then guess your sleep stages from movement. If all you need is to know when to go to bed, that's a lot of battery, data and guesswork for a question arithmetic can answer. This app does the cycle math up front, sets your reminders, and lets your phone charge across the room where it belongs. PRIVATE BY DEFAULT Every calculation happens on your device. No account, no sign-in, no analytics profile, and nothing about your nights is recorded or sent anywhere — the app doesn't track your sleep at all, by design. PREMIUM (PURCHASE REQUIRED) Full Access is available as a weekly subscription, a yearly subscription, or a one-time lifetime purchase. It unlocks all eight sleep sounds, sound mixing with independent volume levels, unlimited wake reminders, and the early wake-up nudge window. Subscriptions renew automatically unless cancelled at least 24 hours before the period ends. Set tomorrow's wake-up time now, pick the bedtime marked Ideal, and see how different the morning feels when your alarm lands between cycles. Terms of Use: https://leanstudio.asia/terms-of-use Privacy Policy: https://leanstudio.asia/privacy-policy Support: [email protected]