Caffeine Half-Life Tracker

Ever wonder why you can't fall asleep even though you had your last coffee "hours ago"? Caffeine doesn't just disappear — it takes roughly 5 hours for your body to eliminate just half of it.

Caffeine Half-Life Tracker shows you exactly how much caffeine is still active in your system right now, and precisely when it will drop low enough for quality sleep.

How it works
Log your drinks as you go — coffee, tea, energy drinks, or anything custom. The app uses your body's caffeine half-life (approximately 5 hours) to calculate a real-time decay curve and tells you when you'll be in the clear.
Features
• One-tap logging for espresso, drip coffee, lattes, green tea, black tea, Red Bull, Monster, Diet Coke, and more
• Real-time mg counter with color-coded status (red → green as caffeine clears)
• Decay graph showing your caffeine curve over the next 12 hours
• Sleep-ready countdown — know exactly when it's safe to wind down
• Custom drink support — add any drink with your own mg amount
• Sleep reminder notification when your caffeine drops below your personal threshold
• Adjustable half-life (3–7h) to match your own metabolism
• Fully offline. No account. No ads. No tracking.

Who it's for
Coffee lovers who want to time their last cup smarter. People who struggle with sleep but haven't connected it to caffeine. Anyone who's ever had a 2 AM heart race and wondered why.

Stop guessing. Start sleeping.