Ever wonder why you can't sleep after a 4pm coffee?
It's not just in your head — caffeine has a half-life of around 5–6 hours, meaning half of it is still in your system hours after your last cup.
I built a free tool that calculates exactly when caffeine will clear your body based on your intake time and amount, so you can plan your last cup without wrecking your sleep.
No login. No data collected. Runs entirely in your browser.