Sleep Calculator
Optimal Bedtime & Wake-up Time Based on Sleep Cycles
Calculate the best times to sleep or wake up based on 90-minute sleep cycles. Plan your sleep scientifically for refreshed mornings.
😴 What are Sleep Cycles?
A sleep cycle lasts approximately 90 minutes and includes 3 stages of NREM sleep and REM sleep. Waking up at the end of a cycle minimizes sleep inertia (grogginess). Completing 4-6 cycles (6-9 hours) per night is ideal for most adults.
(includes 15 min to fall asleep)
📊 Recommended Sleep by Age
| Age Group | Recommended | Acceptable Range |
|---|---|---|
| Newborn (0-3 mo) | 14-17 hours | 11-19 hours |
| Infant (4-11 mo) | 12-15 hours | 10-18 hours |
| Toddler (1-2 yr) | 11-14 hours | 9-16 hours |
| Preschool (3-5 yr) | 10-13 hours | 8-14 hours |
| School Age (6-13 yr) | 9-11 hours | 7-12 hours |
| Teen (14-17 yr) | 8-10 hours | 7-11 hours |
| Adult (18-64 yr) | 7-9 hours | 6-11 hours |
| Senior (65+ yr) | 7-8 hours | 5-9 hours |
📝 How to Use
- Choose a mode: Wake-up time or Bedtime
- "Wake-up mode": Set when you want to wake up to get ideal bedtimes
- "Bedtime mode": Set when you go to bed to get ideal wake-up times
- 15 minutes to fall asleep is automatically included
- Prioritize 5-6 cycle options (7.5-9 hours)
💡 Tips for Better Sleep
- Go to bed and wake up at the same time every day
- Avoid blue light (phone, PC) 1 hour before bed
- Keep bedroom temperature at 65-68F (18-20C)
- No caffeine within 6 hours of bedtime
- Limit naps to 20 minutes or less
❓ FAQ
Sleep follows a ~90-minute cycle from light sleep to deep sleep to REM sleep. Waking at the end of a cycle minimizes sleep inertia (that groggy feeling).
On average, a healthy adult takes about 10-20 minutes to fall asleep. 15 minutes is the commonly accepted average.
Trying to repay sleep debt all at once has limited benefits. A consistent sleep schedule is much healthier for your body and mind.
📚 Panduan perhitungan lokal
Logika rumus
Menggunakan rumus publik untuk keuangan, pinjaman, rasio, dan konversi satuan.
Cakupan sumber
Mengacu pada standar publik dan praktik umum per negara.
Asumsi
Pajak, biaya, suku bunga, dan batas berbeda antar wilayah/lembaga.
Result Interpretation
Gunakan hasil ini sebagai skenario dasar. Sebelum memutuskan, bandingkan dengan penawaran nyata dan aturan pajak lokal.
Preset lokal
Mata uang: IDR
Satuan: metric
Model pajak: US payroll estimate
Catatan regulasi
Alat ini memakai preset regional untuk estimasi. Syarat nyata dan batas hukum dapat berbeda menurut lembaga dan aturan lokal.
Aksi yang disarankan
- Bandingkan minimal 2-3 penyedia lokal sebelum final.
- Cek ulang biaya, pajak, dan klausul pelunasan dipercepat secara tertulis.
- Uji skenario stres dengan bunga +1-2% dan pendapatan turun.
Sebelum keputusan nyata, pastikan aturan terbaru di lembaga setempat.