About Sleep Tools
Free, private, evidence-grounded sleep calculators designed to help you understand your sleep habits without clickbait or pseudo-medical claims.
Our approach
The internet is filled with sleep calculators that promise “optimal 90-minute sleep cycles” or generate arbitrary bedtime prescriptions without clinical basis. Sleep Tools was created with a different standard:
- Evidence-first: We cite established clinical literature (such as consensus statements from the American Academy of Sleep Medicine and Sleep Research Society) and honestly explain the physiological variability of human sleep.
- Privacy-by-design: All calculations run directly in your web browser. Nothing you type is ever uploaded, stored on a remote server, or sold to third parties.
- No false certainty: We do not manufacture automated prescriptions where clinical evidence does not support them. For example, our Sleep Window Guide explains how clinical protocols operate rather than attempting to self-prescribe a restricted sleep schedule.
The tool suite
Bedtime Calculator →
Calculates simple duration-based planning examples (7, 8, or 9 hours in bed) backwards from your target wake-up time.
Sleep Efficiency Calculator →
A lightweight, local sleep log that calculates your mathematical sleep efficiency (Total Sleep Time divided by Time in Bed × 100) using true multi-night aggregation.
Sleep Window Guide →
An educational resource detailing how clinical sleep-window schedules and Cognitive Behavioral Therapy for Insomnia (CBT-I) work in monitored settings.