General planning and education
Sleep Calculator estimates bedtime and wake-up schedules from values you choose. Its educational pages summarize cited sources in plain language. The site does not provide medical advice, diagnosis or treatment, and does not establish a healthcare relationship.
An estimate is not a measurement
A result assumes the entered duration, time to fall asleep, date and time zone. Actual sleep can differ because of awakenings, changes in latency and other circumstances. The tool does not monitor your body, read a wearable, identify sleep stages or determine whether your sleep was restorative.
The default 90-minute cycle length is a mathematical assumption. Cycle lengths vary. A whole-number cycle result does not guarantee a refreshed awakening or make a short sleep duration adequate. Likewise, the default 15-minute latency is an editable input, not a claim about every person.
Age guidance has limits
The age lookup presents general daily recommendations from the CDC. For infants and young children, totals include naps or multiple sleep periods. Adult duration and cycle presets are not an infant or child sleep plan. This site does not give sleep-training, feeding or individualized pediatric advice.
Source tables may use slightly different age boundaries. Sleep Calculator identifies the source it follows rather than presenting its table as the only possible grouping.
Seek qualified advice when needed
If you regularly have trouble sleeping or ongoing tiredness despite adequate sleep opportunity, consult a qualified healthcare professional. Do not use a calculator result to disregard professional advice, stop treatment or diagnose a condition.
The site does not set alarms. Check your chosen date, time zone and alarm in the device or application you normally use. Calculations across a daylight-saving change use elapsed time, which can differ from the clock-face difference.
Sources and commercial independence
Source links do not imply endorsement of Sleep Calculator by the CDC, NIH, NHLBI or AASM. Sleep Calculator does not claim medical certification, clinical review or expert endorsements. No advertising or affiliate program is active in the current version. Future commercial relationships must be disclosed where they appear.
Read About Sleep Calculator for the calculation approach and Privacy Policy for current data practices.