Duration first
A sleep-cycle calculator is a scheduling tool. It should not encourage reducing total sleep simply to land on a mathematically neat cycle boundary.
How much sleep is recommended by age?
Sleep needs change with age. The table below summarizes current CDC guidance and is provided as general population information rather than individual medical advice.
| Age group | Recommended daily sleep |
|---|---|
| 0–3 months | 14–17 hours |
| 4–12 months | 12–16 hours including naps |
| 1–2 years | 11–14 hours including naps |
| 3–5 years | 10–13 hours including naps |
| 6–12 years | 9–12 hours |
| 13–17 years | 8–10 hours |
| 18–60 years | 7 or more hours |
| 61–64 years | 7–9 hours |
| 65+ years | 7–8 hours |
Individual needs vary
Population recommendations are useful context, but sleep needs and sleep quality vary between individuals.
Source: CDC — About Sleep .
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