Guides
Plain-English explanations of how the calculators work and how to get the most from them.
All guides
How bedtime calculators estimate sleep
How the 90-minute sleep-cycle model turns a wake-up time into bedtimes, and why it’s only a starting point.
Free printables
Prefer something on paper? Download a free printable bedtime guide for a 5:15 AM, 6 AM, 6:45 AM or 8 AM alarm.
Put it into practice
Try the bedtime calculator, the wake-up time calculator or check sleep needs by age.