Caffeine Clock: see how much caffeine is still in you
Tap the coffee you just drank. See the milligrams still in your bloodstream right now, how much will be left at bedtime, and when you drop below the level that keeps you awake.
Open the app PricingFree forever. Pro is $2.99/mo for multi-day history.
How it works
- One tap logs a drink — espresso 63 mg, coffee 95 mg, cold brew 200 mg, tea, cola, energy drink, or your own number.
- Caffeine falls by half every 5 hours by default. Set your own half-life between 3 and 7 hours in settings.
- The curve shows the last 12 hours and the next 12, with markers for now and for your bedtime.
- Everything stays on your phone. No account, no sync, nothing sent anywhere.
Why it is useful
"Can I have another coffee at 4pm?" is a question with a number behind it. A 200 mg cold brew at 3pm still leaves about 100 mg in you at 8pm and 50 mg at 1am. Caffeine Clock turns the drink in your hand into that number before you finish it.
It is an estimate from a standard half-life model, not medical advice.
For agents and developers
The same calculation is one HTTP call and one MCP tool. First 50 calls a day are free.
POST https://caffeine-clock.tinyverb.com/api/caffeine-level
{"intakes": [{"mg": 95, "minutesAgo": 120}], "halfLifeHours": 5, "bedtimeInHours": 8}
→ {"currentMg": 71.9, "atBedtimeMg": 23.8, "bedtimeEquivalent": "about a cup of green tea",
"hoursToThreshold": 2.6, "totalMg": 95}