TempoLife › Sleep calculator
Sleep calculator: what time should I go to bed?
Sleep runs in cycles of roughly 90 minutes, and waking mid-cycle makes mornings heavy. Pick your wake-up time (or bedtime) and the calculator suggests times where sleep ends on a cycle boundary. An average 15-minute time to fall asleep is included.
This is a general aid, not medical advice. If you usually take longer than 15 minutes to fall asleep, shift the times accordingly.
How sleep cycles work
Sleep is not one uniform state. Through the night your brain repeats a roughly 90-minute cycle: light sleep, deep sleep and REM. Deep sleep restores the body; REM supports memory and mood.
When the alarm fires during deep sleep you feel groggy even after a long night. Waking at the end of a cycle, in light sleep, feels far clearer — that is the moment this calculator aims for.
A good night for an adult is usually 5–6 full cycles, i.e. 7.5–9 hours of sleep.
How much sleep do you need?
| Age | Recommended sleep |
|---|---|
| Newborn (0–3 mo) | 14–17 h |
| Infant (4–11 mo) | 12–15 h |
| Toddler (1–2 y) | 11–14 h |
| Preschool (3–5 y) | 10–13 h |
| School age (6–13 y) | 9–11 h |
| Teen (14–17 y) | 8–10 h |
| Adult (18–64 y) | 7–9 h |
| 65+ y | 7–8 h |
The table follows the National Sleep Foundation (2015) recommendations. Individual needs vary: if you wake without an alarm feeling rested, you are probably sleeping enough.
How to sleep better
Consistency matters most: go to bed and wake at about the same time every day, weekends included.
Avoid caffeine 6–8 hours before bed and screens right before sleep. A cool (18–19 °C), dark, quiet room deepens sleep.
Daytime activity improves sleep quality; heavy meals and alcohol late in the evening fragment sleep cycles even when falling asleep feels easier.
How TempoLife tracks sleep
TempoLife reads sleep duration and awakenings via Google Health straight from your phone or watch, computes a sleep score and shows trends alongside nutrition and movement.
You see how a late meal, caffeine or a workout actually affects your sleep — from your own data, not generic advice.
Track your sleep automatically
TempoLife brings sleep, nutrition and movement into one free app. Sleep arrives automatically via Google Health — you get the score and the trends.
Frequently asked questions
How many sleep cycles do I need per night?
Adults need 4–6 cycles. Five cycles (7.5 hours) suit most people; under four leaves most people tired.
Is 6 hours of sleep enough?
For most adults, no. The recommendation is 7–9 hours. Six hours is exactly 4 cycles and can work briefly, but consistently sleeping under 7 hours is linked to worse focus, appetite control and health markers.
Why do I wake up tired after 8 hours of sleep?
Often the alarm lands in deep sleep. Try moving your alarm to a cycle boundary (calculator above) and review sleep quality: alcohol, late caffeine and an irregular schedule fragment sleep.
How long does falling asleep normally take?
About 10–20 minutes for a healthy person. The calculator uses 15 minutes — if you usually take longer, shift the suggested times earlier.
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📊 meals logged · 3 470 step-days · 715 sleep nights — built in Estonia
