This bedtime, wake-up time, and sleep duration calculator estimates a practical schedule from the time you must wake or get into bed, your age-based sleep target, and the time you expect to need to fall asleep. Adequate total sleep and a consistent schedule matter more than matching a predicted cycle boundary.
Enter a local clock time.
If this is earlier than bedtime, it is treated as the next day.
Child and infant totals are per 24 hours and may include naps.
Optional for adults: set a minimum and maximum from 6 to 12 hours.
Enter 0–120 minutes. Default: 15 minutes; use your usual estimate.
Enter 70–120 minutes; try 80, 90, or 100. This changes only the approximate cycle count.
Customization can improve planning, but clock times cannot predict biological sleep stages with medical precision.
Using an 8-hour adult sleep target and 15-minute sleep latency:
Fall asleep: 6:30 AM − 8 hours = 10:30 PM the previous day
Get into bed: 10:30 PM − 15 minutes = 10:15 PM
Estimated cycles: 480 ÷ 90 ≈ 5.3
Using the same 8-hour target and 15-minute sleep latency:
Fall asleep: 11:00 PM + 15 minutes = 11:15 PM
Wake: 11:15 PM + 8 hours = 7:15 AM the next day
Time in bed: 8 hours 15 minutes
The calculator uses these ranges to rank plans. Guidance comes from the CDC sleep recommendations, which incorporate AASM pediatric guidance. Infant, toddler, and preschool totals include naps.
| Age group | Recommended sleep per 24 hours | Calculator target |
|---|---|---|
| Infant, 4–12 months | 12–16 hours, including naps | 12–16 hours |
| Toddler, 1–2 years | 11–14 hours, including naps | 11–14 hours |
| Preschool, 3–5 years | 10–13 hours, including naps | 10–13 hours |
| School age, 6–12 years | 9–12 hours | 9–12 hours |
| Teen, 13–17 years | 8–10 hours | 8–10 hours |
| Adult, 18–60 years | 7 or more hours | 7–9 hour planning range; editable |
| Adult, 61–64 years | 7–9 hours | 7–9 hours; editable |
| Adult, 65+ years | 7–8 hours | 7–8 hours; editable |
The adult 7–9 hour range is a practical planning window, not an upper medical limit. AASM recommends at least 7 hours for healthy adults and notes that more than 9 hours may be appropriate for some people.
Recommended get-into-bed time = wake time − target sleep − sleep latency.
Recommended wake time = get-into-bed time + sleep latency + target sleep.
Estimated cycles = estimated sleep duration ÷ selected cycle length.
Time in bed = wake time − get-into-bed time. Estimated time asleep = time in bed − sleep latency. They are not the same measurement.
Clock arithmetic wraps across midnight. For example, a wake time earlier on the clock than bedtime is treated as occurring the next day. The duration mode assumes a sleep period shorter than 24 hours.
The transition from wakefulness into sleep.
A period of established sleep that occurs repeatedly through the night.
Deep, slow-wave sleep. People generally spend more time in this stage earlier in the night.
A stage associated with active brain patterns and most dreaming. REM periods generally become more prominent later in the night.
According to the NIH National Heart, Lung, and Blood Institute, the NREM–REM sequence restarts about every 80–100 minutes and people usually have four to six cycles per night. These are observed patterns, not fixed 90-minute blocks, which is why adequate sleep duration takes priority in this calculator.
Needs generally decrease from 12–16 hours per 24 hours for infants aged 4–12 months to 8–10 hours for teens. Healthy adults aged 18–60 should regularly get at least 7 hours. Use the table above for every age group.
No. NHLBI says cycles typically restart every 80–100 minutes, and timing varies between people and across the night. The editable cycle length provides an approximate count only.
Time in bed is not always time asleep, and sleep quality, schedule timing, interruptions, illness, medicines, or an unrecognized sleep disorder may affect how rested you feel.
No. A clock cannot determine your live sleep stage. Total sleep, regularity, sleep quality, and your individual needs are more useful priorities.
There is no single correct latency for everyone. The 15-minute default is a planning assumption. If it regularly takes more than about 30 minutes or the problem affects daytime activities, discuss it with a healthcare professional.
Not as a regular target for most people. Both are below recommended ranges for children and teens, and below the adult recommendation of at least 7 hours.
Select it once and the calculator uses your device’s current local time as get-into-bed time, then immediately calculates age-targeted wake-up options.
Talk with a healthcare professional when persistent insomnia, unrefreshing sleep, or daytime sleepiness affects daily life. Loud habitual snoring, gasping, choking, or observed breathing pauses can be signs of sleep apnea and warrant prompt medical advice. Do not use this calculator to delay care.
Editorial owner: Starlight Tools, a Starlight Robotics project
Last editorial review: 16 July 2026
Medical review: Not performed. No medical reviewer is claimed.
This educational calculator does not diagnose sleep disorders or replace individualized medical advice.
