Bedtime Calculator

About

Bedtime Calculator is a simple browser-based tool for planning sleep around 90-minute cycles.

The calculator helps with two common questions: when to go to bed for a target wake time, and when to wake up if you are heading to bed now.

Results are based on a 90-minute cycle model plus a configurable fall-asleep buffer. The tool is informational only. It is not medical advice and it does not diagnose sleep disorders.

Everything runs in the browser. There is no account system, no saved history, and no server-side storage of your calculator inputs in this Phase 1 release.