Calculator
Sleep Calculator
Sleep runs in roughly 90-minute cycles. Waking at the end of one, rather than mid-cycle, is why five full cycles can feel better than seven broken hours.
min
Fifteen minutes is average. Longer is common in perimenopause.
Sleep Calculator
Calculate optimal sleep and wake times based on your sleep cycles for better rest
When to Sleep
I need to wake up at a specific time – when should I go to bed?
⏰ When to Wake Up
I’m going to bed now – when should I wake up?
Optimal Sleep Times
Sleep Analysis
Sleep Quality Tips:
- Keep a consistent sleep schedule, even on weekends
- Create a relaxing bedtime routine 30-60 minutes before sleep
- Avoid screens and blue light 1 hour before bedtime
- Keep your bedroom cool (60-67°F), dark, and quiet
- Avoid caffeine 6+ hours before bedtime
- Get natural sunlight exposure during the day
- Exercise regularly, but not close to bedtime
About this calculator
- Gives recommended bedtimes if you must wake at a set hour, or wake times if you’re going to bed now.
- Uses ~90-minute sleep cycles and your settling time (minutes it takes to fall asleep).
- Highlights 5–6 cycles (7.5–9 h) as commonly restorative for adults.
How to use it
- Choose a mode: When to Sleep or When to Wake Up.
- Enter your target time (wake time or bedtime) and your time to fall asleep.
- Review several options; pick the one that fits your schedule and feels realistic.
What your result means
- Times are aligned to the end of a sleep cycle, when waking usually feels easier.
- If you wake before the alarm and feel good, it’s okay to get up—you likely finished a cycle.
- If you wake groggy, try shifting bedtime/wake time by ±15–30 minutes and keep the new time for a few days.
Tips for better sleep
- Keep a consistent schedule, even on weekends.
- Start a 30–60 min wind-down: dim lights, read, stretch, breathe.
- No screens/blue light in the last hour if you can help it.
- Keep the bedroom cool, dark, and quiet; consider white noise or earplugs.
- Avoid caffeine within 6–8 hours of bed; go easy on late alcohol.
- Get daylight soon after waking and move your body during the day.
Special situations
- Teens & young adults often need 8–10 hours.
- Shift workers: anchor 1–2 consistent sleep blocks; use blackout curtains and a wind-down routine.
- Parents & caregivers: naps (20–30 min) can help; protect your next night’s sleep by avoiding long, late naps.
- Snoring, gasping, or persistent insomnia: ask a clinician—sleep disorders are common and treatable.
FAQs
- Why 90 minutes?
A typical cycle of light, deep, and REM sleep averages about 90 minutes, though people vary. - Is more always better?
Up to a point. Many adults feel best between 7–9 hours, but needs differ. - What about naps?
Try 20–30 minutes (easy to wake) or ~90 minutes (a full cycle). Avoid long naps late in the day. - I take a long time to fall asleep—what should I enter?
Add your best estimate (e.g., 20–30 minutes) so the calculator shifts bedtimes earlier. - Medical advice?
This is educational, not medical care. Seek help for ongoing sleep problems, excessive daytime sleepiness, or loud snoring.
