A small library for quieter nights
Sleep guides
Use clear context to plan sleep while keeping estimates in perspective.
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01 / Foundations
How sleep cycles work
Learn how REM and non-REM stages repeat, why cycles vary, and how the 90-minute planning model works.
Read the guide 02 / Sleep latencyHow long does it take to fall asleep?
Learn why sleep onset varies and how to set a flexible bedtime estimate.
Read the guide 03 / Sleep durationHow much sleep do I need?
Compare age-based sleep-duration ranges with your own routine and daily needs.
Read the guide 04 / Wake planningWhat time should I wake up?
Work backward from tomorrow's commitments, your sleep need, and a little room for cycles and sleep onset.
Read the guidePlan your night with the bedtime calculatoror sleep cycle calculator. Explore the sleep-needs calculator.