About SleepCycleCalc

SleepCycleCalc exists because of a very common, very fixable frustration: sleeping a reasonable number of hours and still waking up feeling like the night never happened. Often the hours were fine — the timing was not. The alarm landed in the middle of deep sleep.

The tools here are built on one well-established idea: sleep runs in cycles of roughly 90 minutes, and waking near the end of a cycle usually feels easier than waking in the middle of one. Around that idea we built the smallest useful set of tools — a sleep cycle calculator, dedicated bedtime and wake-up calculators, a nap calculator, a sleep debt estimator, and plain-language guides to how cycles work and how much sleep each age group needs.

What we are careful about

• The 90-minute figure is an average. We say so on every page. Real cycles run about 80–110 minutes.
• This is not medical advice. Calculators cannot diagnose sleep apnoea, insomnia, or anything else. Persistent problems belong with a doctor.
• Your data stays yours. Everything runs in your browser; there are no accounts and nothing is uploaded.
• Consistency beats precision. We would rather you kept a steady wake time with our rough numbers than chased a perfect bedtime once a month.

SleepCycleCalc is built and maintained by Jimmy | ORBITFRAME, an independent front-end developer, as part of a family of small, free, single-purpose calculators.