?

😴 Sleep Calculator

Calculate the best times to go to sleep or wake up based on your sleep cycles. Wake up feeling refreshed and energized.

I'm Going to Bed At...

:

Sleep Cycle Info

Each sleep cycle is ~90 minutes. Waking between cycles helps you feel more rested.

? Best Times to Wake Up

5:15 AM 4 sleep cycles
6h sleep
9:45 AM 7 sleep cycles
10.5h sleep

? I Need to Wake Up At...

:

Best Times to Go to Sleep

9:46 PM 6 sleep cycles ? Optimal
9h sleep
12:46 AM 4 sleep cycles
6h sleep
2:16 AM 3 sleep cycles
4.5h sleep

Power Nap Calculator

:

Nap Timing

Avoid napping after 3 PM as it can interfere with nighttime sleep.

Nap Schedule

Recommended Nap Types

Power Nap (10-20 min): Boosts alertness without grogginess

? Short Nap (30 min): Good for memory and creativity

Full Cycle (90 min): Complete sleep cycle, best recovery

Understanding Sleep Cycles

Sleep isn't a uniform state×it occurs in cycles of distinct stages that repeat throughout the night. Understanding these cycles helps you wake up feeling refreshed rather than groggy.

Light Sleep

~25 min

Stages 1 & 2. Easy to wake from. Heart rate slows, muscles relax.

Deep Sleep

~25 min

Stage 3. Body repairs, immune system strengthens. Hard to wake.

REM Sleep

~25 min

Dreams occur. Brain processes memories and emotions.

Why 90-Minute Cycles Matter

A complete sleep cycle lasts approximately 90 minutes. Waking at the end of a cycle (during light sleep) feels natural, while waking during deep sleep causes grogginess and sleep inertia that can last 30+ minutes.

Sleep Recommendations by Age

Age Group Recommended Sleep Sleep Cycles
Newborn (0-3 months) 14-17 hours Variable
Infant (4-11 months) 12-15 hours 8-10 cycles
Toddler (1-2 years) 11-14 hours 7-9 cycles
Preschool (3-5 years) 10-13 hours 7-9 cycles
School Age (6-13 years) 9-11 hours 6-7 cycles
Teenager (14-17 years) 8-10 hours 5-7 cycles
Adult (18-64 years) 7-9 hours 5-6 cycles
Older Adult (65+) 7-8 hours 5-6 cycles

Tips for Better Sleep

Screen-Free Before Bed

Stop using phones, tablets, and computers 1 hour before bed. Blue light suppresses melatonin production.

Keep It Cool

Ideal bedroom temperature is 60-67×F (15-19×C). Your body needs to cool down to initiate sleep.

? Consistent Schedule

Go to bed and wake up at the same time daily, even on weekends. This strengthens your circadian rhythm.

? Limit Caffeine

Avoid caffeine at least 6 hours before bed. It has a half-life of 5-6 hours in your system.

Dark Environment

Use blackout curtains and remove all light sources. Even small lights can disrupt sleep quality.

Relaxation Routine

Develop a pre-sleep routine: reading, stretching, meditation, or a warm bath 1-2 hours before bed.

Sleep Needs by Age: National Sleep Foundation Guidelines (2026)

The National Sleep Foundation and American Academy of Sleep Medicine recommend these sleep durations based on age. Both getting too little and too much sleep are associated with negative health outcomes:

Age Group Recommended Sleep May be Appropriate Not Recommended
Newborns (0×3 months)14×17 hours11×13 or 18×19 hrs<11 or >19 hrs
Infants (4×11 months)12×15 hours10×11 or 16×18 hrs<10 or >18 hrs
Toddlers (1×2 years)11×14 hours9×10 or 15×16 hrs<9 or >16 hrs
Preschoolers (3×5 years)10×13 hours8×9 or 14 hrs<8 or >14 hrs
School-age children (6×13)9×11 hours7×8 or 12 hrs<7 or >12 hrs
Teenagers (14×17 years)8×10 hours7 or 11 hrs<7 or >11 hrs
Young adults (18×25)7×9 hours6 or 10×11 hrs<6 or >11 hrs
Adults (26×64)7×9 hours6 or 10 hrs<6 or >10 hrs
Older adults (65+)7×8 hours5×6 or 9 hrs<5 or >9 hrs
Sleep Cycle Timing: Each sleep cycle lasts approximately 90 minutes. Waking at the end of a cycle (rather than mid-cycle) leaves you feeling more refreshed. To find optimal wake times: count back in 90-minute increments from when you need to wake up, then add 15 minutes to fall asleep. Example: Wake at 7:00 AM ? sleep at 11:45 PM (4 cycles) or 10:15 PM (5 cycles).

? Frequently Asked Questions

Why do I feel tired even after 8 hours of sleep? +
You might be waking during deep sleep rather than at the end of a cycle. Try adjusting bedtime by 15-30 minutes. Other factors include poor sleep quality, sleep apnea, inconsistent schedule, or underlying health issues. Quality matters as much as quantity.
Is it bad to hit the snooze button? +
Yes! Snoozing leads to "sleep fragmentation" where you enter a new sleep cycle you can't complete. This causes sleep inertia×that groggy, disoriented feeling. It's better to set your alarm for when you actually need to get up.
Can I catch up on sleep during weekends? +
Partially, but not fully. "Sleep debt" can be partially recovered, but irregular schedules disrupt your circadian rhythm, causing "social jet lag." It's better to maintain consistent sleep times and add no more than 1 hour on weekends if needed.
What's the best time to take a nap? +
The ideal nap time is early-to-mid afternoon (1-3 PM), when you naturally experience a dip in alertness. Avoid napping after 3 PM as it can interfere with nighttime sleep. Keep naps to 20 minutes or a full 90-minute cycle to avoid grogginess.
How long does it take to fall asleep? +
The average adult takes 10-20 minutes to fall asleep (sleep latency). If you fall asleep instantly (under 5 minutes), you may be sleep-deprived. If it takes longer than 20-30 minutes consistently, you might have insomnia or need to adjust your sleep habits.