# SleepCalculator

> Evidence-based sleep timing, bedtime calculation, and sleep cycle estimation platform.

Free, scientifically modeled algorithms based on peer-reviewed circadian science and sleep architecture.

## Calculators & Tools

- [Sleep Calculator](https://sleepcalculator.dev/sleep-calculator/): Calculate bedtimes, wake-up times, and optimal sleep cycles.
- [Sleep Cycle Calculator](https://sleepcalculator.dev/sleep-cycle-calculator/): Interactive sleep stage timeline visualizer across 90-minute ultradian cycles.
- [Bedtime Calculator](https://sleepcalculator.dev/bedtime-calculator/): Calculate exact bedtimes for fixed morning alarm schedules.

## Sleep Science Guides & Blog

- [Sleep Guides & Blog](https://sleepcalculator.dev/blog/): Evidence-based library of circadian science and sleep schedule research.
- [Sleep Calculator Cycles](https://sleepcalculator.dev/blog/sleep-calculator-cycle/): Clinical guide on how 90-minute ultradian cycles determine optimal bedtimes, wake times, and eliminate sleep inertia.
- [Sleep Calculator by Age](https://sleepcalculator.dev/blog/sleep-calculator-by-age/): Recommended sleep duration, cycles, and hormonal variations across every life stage (newborns to seniors, gender differences).
- [Sleep Calculator Wake-Up Time](https://sleepcalculator.dev/blog/sleep-calculator-wake-up-time/): How to calculate optimal bedtimes from fixed morning alarms and avoid the snooze trap.
- [How Many Hours of Sleep Do You Need?](https://sleepcalculator.dev/blog/sleep-calculator-how-many-hours/): Debunking the 8-hour myth, measuring sleep efficiency, and calculating sleep debt.
- [Power Nap & Jet Lag Guide](https://sleepcalculator.dev/blog/sleep-calculator-nap/): The 20-min power nap vs 90-min full cycle, caffeine nap protocol, and East-West timezone shift rules.

## About & Contact

- [About Us](https://sleepcalculator.dev/about/): Platform mission and principles.
- [Contact](https://sleepcalculator.dev/contact/): Feedback and inquiries.