Sleep Cycle Calculator

About This Tool

Waking up groggy even after 8 hours of sleep? You likely woke up in the middle of a deep sleep cycle. The Sleep Calculator helps you time your sleep to align with your body's natural 90-minute circadian rhythms. By waking up at the end of a cycle (when you are in light sleep), you feel refreshed and alert. Use this tool to work backward from your alarm clock to find your ideal bedtime, or forward from 'now' if you are heading to sleep. Understanding your body metrics is the first step toward achieving your health and fitness goals. This calculator uses scientifically validated formulas endorsed by health organizations worldwide, ensuring accuracy you can trust. The results provide personalized insights that help you make informed decisions about your diet, exercise routine, and lifestyle choices. Whether you're trying to lose weight, build muscle, or simply maintain a healthy lifestyle, this tool gives you the data-driven guidance you need. It's perfect for fitness enthusiasts, athletes, nutritionists, and anyone committed to improving their health through measurable, evidence-based approaches. Our algorithms are optimized for performance, ensuring instant results even for complex calculations. We are committed to providing free, high-quality tools to help you be more productive.