Sleep Need Calculator
Recommended Sleep Changes More Than Most People Realize
The "8 hours a night" figure gets applied to everyone from teenagers to retirees, but recommended sleep duration actually shifts substantially across the lifespan — a newborn needs roughly double what an older adult does. This calculator looks up the recommended nightly range for a given age based on established age-based sleep guidelines rather than defaulting to a single number for everyone.
Recommended Sleep by Age Group
Rather than a formula in the algebraic sense, this calculator matches the entered age to one of eight age bands, each with its own recommended range, drawn from widely cited pediatric and adult sleep guidelines.
Reference Table
| Age group | Recommended sleep |
|---|---|
| Newborn (0–3 months) | 14–17 hours/day |
| Infant (4–11 months) | 12–15 hours/day |
| Toddler (1–2 years) | 11–14 hours/day |
| Preschool (3–5 years) | 10–13 hours/day |
| School Age (6–13 years) | 9–11 hours/night |
| Teen (14–17 years) | 8–10 hours/night |
| Adult (18–64 years) | 7–9 hours/night |
| Older Adult (65+ years) | 7–8 hours/night |
Individual sleep need can vary by roughly ±1 hour depending on genetics, activity level, and general health.
Where This Matters
- Setting a realistic target — before using the Sleep Debt Calculator, you need an accurate recommended figure for your age rather than a generic 8 hours.
- Parents tracking a child's sleep — recommended ranges for infants and toddlers are dramatically higher than adult figures, and this flags the correct band automatically.
- Understanding changes with age — the gradual decline in recommended sleep from childhood through older adulthood explains why the same schedule that worked at 20 may need adjusting later.
How to Use This Calculator
- Enter age in years in the Age field (decimals accepted, e.g. 0.5 for a 6-month-old).
- Select Calculate to see the recommended nightly sleep range for that age group.
Related Calculations
Once you know your target, track whether you're meeting it with the Sleep Debt Calculator, or plan a cycle-aligned bedtime with the Bedtime Calculator.