Stop waking up groggy. Wake up between cycles.
Sleep runs in ~90-minute cycles. Wake up in the middle of one and you feel wrecked. Wake up between them and you feel refreshed. Enter your time and we'll do the math.
Sleep Calculator
Based on 90-minute sleep cycles
Why timing beats total hours
Eight hours in bed means nothing if your alarm rips you out of deep sleep. Here's what's actually happening while you're out.
Cycles run ~90 minutes
Each night you move through repeating cycles of light sleep, deep sleep and REM. One full loop takes roughly 90 minutes.
Aim for 5 to 6 cycles
A complete night is five to six full cycles, about 7.5 to 9 hours. Fewer and you carry sleep debt; more rarely helps.
Wake between cycles
Wake in the middle of a cycle and you feel foggy and heavy. Wake in the gap between two cycles and you feel clear and rested.
One night, five cycles
The calculator gives you a target. The Hume Band tells you if you hit it.
A bedtime is a plan. But most people have no idea how much of that time was actually deep, restorative sleep, or how many times they surfaced without remembering it.
- See your real light, deep, REM and awake stages, night after night.
- Track how well your body actually recovered, not just how long you were in bed.
- Watch your sleep debt build up, and close it, across the week.
Sleep tracking that reads your body, not just your bedtime
A comfortable screen-free band you barely feel. It works while you sleep so you wake up to answers, not guesses.
Full sleep-stage breakdown
Light, deep, REM and awake, mapped through the night by a patented algorithm so you can see where the good sleep actually went.
Overnight HRV & recovery
Tracks heart-rate variability while you sleep to show how well your body rebuilt itself, the truest signal of recovery.
Weekly sleep-debt view
See your sleep pile up or pay down across the week, with clear recommendations to get your schedule back on track.
Wears all night, comfortably
No screen glowing on your wrist, no bulky watch digging into the pillow, just a soft band that logs every cycle.
Habits that protect your cycles
Nailing your bedtime helps. These make the sleep you get actually count.
Keep one schedule
Go to bed and wake up at the same time, weekends included. Your cycles lock into a rhythm and mornings get easier.
Kill screens an hour before
Blue light suppresses melatonin and pushes your bedtime later. Power down devices about 60 minutes before you sleep.
Cool, dark and quiet
A cooler room and true darkness help you fall, and stay, in deep sleep. Aim for around 65–68°F.
Cut caffeine early
Caffeine can linger 6+ hours. Keep it to the morning so it isn't still working when your head hits the pillow.
Get morning light
Bright light soon after waking anchors your body clock and makes falling asleep on time that night far easier.
Wind down on purpose
A calm routine of reading, stretching and slow breathing signals your body it's time to shift into sleep.
Sleep cycles, answered
It takes the average person about fifteen minutes to fall asleep, so this calculator builds that buffer into every bedtime it suggests.
Each cycle lasts about 90 minutes. A good night's sleep is five to six complete cycles, roughly 7.5 to 9 hours in total.
Waking in the middle of a cycle, especially out of deep sleep, leaves you foggy and heavy. Waking in the gap between two cycles is what lets you get up feeling clear and refreshed.
It counts backward (or forward) in 90-minute cycles from your chosen time, adds the ~15 minutes it takes to fall asleep, and lands each suggested time at the end of a full cycle so you wake between them.
The calculator plans your ideal bedtime. The Hume Band 2.0 measures what actually happened: your real light, deep, REM and awake stages, HRV and recovery, so you can see whether you truly hit your target night after night.
Plan the perfect night. Then prove you had it.
Use the calculator to find your bedtime, and let the Hume Band 2.0 show you exactly how your body slept.
Shop the Hume Band 2.0 →