About Sleep Schedule

Who built this

Sleep Schedule was built by a software developer with a long-standing interest in sleep science — because most sleep tools out there are inaccurate, ad-heavy, or ignore the underlying biology of sleep cycles.

All calculators on this site are built on peer-reviewed sleep science and published health authority guidelines — not guesswork.

The science behind it

Human sleep is organized into 90-minute cycles. Each cycle moves through three stages: light sleep (N1/N2), deep sleep (N3), and REM. Waking at the end of a cycle — rather than mid-cycle — dramatically reduces sleep inertia (grogginess).

The bedtime and wake-up calculators on this site work backwards from your target time, subtracting complete 90-minute cycles and adding a 15-minute fall-asleep buffer (the average onset latency for adults).

Sleep duration targets are based on CDC sleep guidelines by age group. REM estimates use polysomnography averages from peer-reviewed sleep research. Pregnancy recommendations follow ACOG and NSF guidance. Baby sleep guidelines follow the American Academy of Pediatrics (AAP).

Medical disclaimer

Sleep Schedule provides general health information only and is not a substitute for professional medical advice. Always consult your doctor or a qualified healthcare provider if you have concerns about your sleep or health, especially during pregnancy or for infants.

The calculators

• Sleep Calculator — Find your ideal bedtime or wake-up time from 90-minute cycles
• Nap Calculator — 20-min power nap vs 90-min full cycle — avoid grogginess
• REM Sleep Calculator — Estimate REM time from your total sleep hours
• Sleep Debt Calculator — How far short are you of your CDC target?
• Sleep Duration Calculator — Age-based sleep needs from CDC guidelines
• Pregnancy Sleep Calculator — Trimester-specific sleep guidance based on ACOG and NSF
• Baby Sleep Calculator — Infant sleep schedules by age per AAP guidelines