Caffeine Half-Life Visualizer
See exactly how wired you’ll still be at 4PM after a 3AM Red Bull.
A small tool that models the caffeine in your system over 24 hours using half-life math. Log one dose or five and watch the decay curve, so you can time your last coffee before it wrecks your sleep. Built because every explanation online was needlessly complicated.
The motivation
I used to drink a lot of caffeine before exams and had no real sense of when it would hit or when it would wear off. Everything online was either hand-wavy or a wall of pharmacology, so I built the version I actually wanted: enter a dose and a time, and just see the curve.
How it works
Each dose decays on caffeine’s half-life, and the tool sums the doses to plot your combined level across a 24-hour window. Add a second Red Bull at 3AM and you can watch precisely how much is still in your system when your alarm goes off.
Why it’s here
It’s deliberately tiny — no login, no setup, just answer the question and get out of the way. It’s the clearest example of how I like to work: notice a small, real annoyance and build the smallest good tool that removes it.