時間ツール
睡眠時間計算機
睡眠サイクルと年齢別の目安から、就寝時刻や起床時刻を計算します。
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使い方
- Choose whether you need to wake up at a target time or plan from a bedtime.
- Enter the date, time zone, estimated time to fall asleep and cycle length. Choose an age range when you want a duration check.
- Select Calculate, then review the dated schedule, timeline and first sleep-window reference. Copy or download the schedule if useful.
おすすめの用途
- Planning a consistent bedtime
- Checking a morning schedule across time zones
- Comparing cycle estimates with total sleep duration
注意点
This is a planning aid, not a sleep monitor. Sleep cycles vary between people and across a night; age guidance is general population guidance, not a medical prescription.
よくある質問
What time should I go to bed?
Enter the time you need to wake up. The calculator subtracts the selected number of estimated cycles and your fall-asleep buffer, then shows dated bedtime options.
What time should I wake up?
Enter your bedtime, or select estimated sleep time if you already know when you usually fall asleep. The calculator adds the selected cycles to that instant.
Is every sleep cycle exactly 90 minutes?
No. Ninety minutes is a convenient planning estimate. NIH describes typical cycles as roughly 80–100 minutes, and cycle length varies between people and across a night.
How many sleep cycles do I need?
Most adults need at least seven hours of sleep, which may be around five cycles at a 90-minute estimate. Total sleep duration matters more than mechanically matching a multiple.
Is 6 hours of sleep enough?
Six hours is below the usual recommendation for most adults. A complete estimated cycle does not make a short night sufficient; consider the duration label and protect enough time for sleep.
What are the first 90 minutes of sleep?
The first-sleep-window card shows an approximate 90-minute window after estimated sleep onset. It is a planning reference, not a measurement of deep sleep or a guarantee of sleep quality.
Can this calculator detect REM sleep?
No. A browser calculator cannot detect REM or non-REM sleep. Actual stages require professional sleep monitoring.
Does this tool diagnose sleep problems?
No. It does not diagnose insomnia, sleep apnea or any other condition. Seek professional advice for persistent insomnia, loud snoring, breathing pauses or daytime sleepiness.
Is my sleep information uploaded?
No. Dates, times, age selection and time-zone calculations stay in your browser. Calendar files are generated locally and input values are not sent to analytics.