Caffeine Clock

How wired are you right now?

Log what you drank and when. We'll model caffeine's decay in your system using its actual half‑life, so you can see when you'll likely be clear enough to sleep.

How wired are you

0 mg active now Clear
Today's peak 0 mg
≈ cups active 0
Half‑life 5.0 hr
🌙 Log a drink to see your bedtime forecast.

Caffeine curve

Active caffeine Clear threshold Now

Profile

Personalizes your forecast.

Affects how strong a dose feels, not clearance speed — that's mostly genetic.
50 mg
Most people feel minimal effects below this. Sensitivity varies a lot person to person.

Log a drink

Choose what you had, confirm when, then log it.

What did you have?
When did you have it? Now

Today's drink history

Tap × to remove an entry.

🍵 Still climbing this late? A low‑caffeine tea keeps the ritual going without pushing your bedtime back. Shop low‑caffeine tea →
For general awareness only — not medical advice. Caffeine half‑life varies widely by genetics, liver function, pregnancy, medications, and other factors; figures here are population averages. Coffee is estimated at 65mg/oz (espresso), 12mg/oz (drip), 14mg/oz (cold brew); matcha at ~30mg/g of powder, hojicha at ~7mg/g — actual strength varies by brew ratio, brand, and product. If you're pregnant, nursing, or sensitive to caffeine, talk to a healthcare provider.