Sleep & Health Check Calculators
Quick checks for everyday health questions, starting with when to go to bed or wake up around 90-minute sleep cycles. They are for information only and never replace a clinician.
How these calculators work
Every calculator in this group names its formula, shows a worked example and lists the sources behind its categories. The numbers are estimates based on the details you enter, so they work best as a starting point for a conversation with a doctor, dietitian or trainer rather than as a final answer.
Results are for information only and are not medical advice. See our editorial policy and methodology for how we choose and review formulas.