Circadian Energy shows you your personal energy curve, so you know when you're at your best.
Scan with your iPhone
Energy isn't constant. Circadian Energy shows your body's natural rhythm.
Your energy curve right on the Lock Screen. No need to open the app.
Your personal curve shows you hour by hour how your energy unfolds.
No subscription. No fine print. Buy once, keep forever.
Understand your energy without feeling bad about it.
Circadian Energy shows your curve. It doesn't tell you what to do. Your day, your call.
No sleep score. No sleep debt number. No judgment. The curve is the information.
Circadian Energy emphasizes when you can be at your best, not when you're tired.
Your widget shows everything at a glance. Notifications only when you want them.
The science behind sleep and energy. Every article backed by peer-reviewed research.
What happens when you chronically undersleep? Calculate your deficit.
Self-TestEarly bird or night owl? Your chronotype determines when you perform best.
ScienceThe two-process model explains your afternoon slump and your peak times.
Trending 2026A social media trend with real substance. What the research says.
Self-Test10 evidence-based rules for better sleep.
Interactive CalculatorWhy you get tired after lunch, and what causes it.
Interactive CalculatorCalculate your ideal bedtime and wake time.
ScienceWhat heart rate variability says about your sleep.
Sources: Borbély (1982), Achermann (2004), Roenneberg et al. (2007), Dijk (2009), Shaffer & Ginsberg (2017), Buchheit (2014), Nicolò et al. (2020), Ekkekakis (2003), Khalsa et al. (2003), Kaminsky et al. (2015)
Your health data never leaves your iPhone.