Caffeine Tracking

The "I drink coffee but want to sleep" page. For coffee gear / brewing / roasting see Coffee Roasting & Tracking; for caffeine via tea / energy drinks / sodas see Water & Beverage Tracking; for general nutrition tracking that includes caffeine see Nutrition Tracking — Cronometer & MyFitnessPal; for the data underneath caffeine values per food see Food Databases & Open Food Facts.

Apps focused on caffeine

• ★ HeyMaja — paid + free; clean iOS / Android; circadian-rhythm-aware; predicts when caffeine will affect your sleep based on dose + half-life. The most data-driven of the consumer caffeine apps.
• Caffeine Tracker (multiple, varying maturity) — most are basic logger + total / day.
• Up Coffee — sunset; ignore (was Jawbone).
• Caffeine Calculator by Coffee And Health — free web; one-shot.

In existing trackers (the better answer for most)

• ★ Cronometer — caffeine value is a tracked nutrient row; logging your coffee / tea / energy drink already gives you total mg/day with no extra app.
• MyFitnessPal — same; less accurate values, depends on the entry.
• Apple Health caffeine — manually-logged; pairs with Whoop / Oura / Garmin.
• Garmin Connect — has caffeine + sleep coaching since 2024.
• Whoop — has caffeine logging; ties to recovery score.
• Oura — added caffeine logging in 2024-25; ties to sleep score.

For most people, Cronometer's caffeine row + Oura/Whoop sleep correlation is the right setup; a separate caffeine app is over-tooling.

Reference values (mg caffeine per typical serving)

The half-life rule (the actual point)

• Caffeine half-life is ~5 hours in healthy adults; longer (8+ h) in slow CYP1A2 metabolizers, in pregnancy, with hormonal contraceptives.
• A 200 mg coffee at noon = ~100 mg at 5pm = ~50 mg at 10pm. That's still enough to reduce deep sleep.
• Cutoff for most people: 8–10 hours before bed. That's noon for a 10pm bedtime.
• Genetic test (23andMe, AncestryDNA's CYP1A2) — tells you if you're a fast or slow metabolizer; useful self-knowledge.

Sleep-correlation insights (the win)

• ★ Whoop / Oura / 8 Sleep + caffeine log — over a few weeks, the correlation between caffeine timing and HRV / deep sleep is dramatic and personal. You'll change your habits.
• HeyMaja's "predicted sleep impact" — does this without needing a wearable.
• Cronometer + Apple Health Sleep — workable; manual analysis.

Cycling / withdrawal / tolerance

• Caffeine tolerance builds in 7–10 days of consistent dosing; resets in similar timeframe.
• Withdrawal headaches are real; taper if cutting.
• "Caffeine cycling" (1 week off / 3 weeks on, etc.) is fitness-influencer-flavored; weak evidence; mostly you-do-you.
• Theanine (200 mg) + caffeine evens out the jitter; well-supported.

Self-host / DIY

• A Cronometer-only setup is the right path.
• Apple Shortcuts: tap-and-log a coffee; writes to Health.
• Google Sheet + iOS Shortcut — cheap caffeine log; pair with a sleep wearable export.
• Pandas + Whoop / Oura CSV exports — for the curious; correlate caffeine timing with HRV + deep sleep yourself.
• Wger — no caffeine module specifically; nutrition module catches it incidentally.

Practical guidance

• ★ Don't track caffeine in isolation. It's only useful next to sleep / HRV / energy data.
• A morning caffeine + an early-afternoon caffeine is the high-mileage pattern. Skip the post-3pm cup.
• Taper, don't quit cold. Withdrawal headaches are 3–5 days of misery.
• Pre-workout fans, watch the dose. 300+ mg one-shot is lots; can dent sleep that night.
• Pregnancy / trying-to-conceive: caffeine guidelines are <200 mg/day; the half-life is much longer in pregnancy.
• Energy drinks aren't dose-tracked well by most apps. Read the label; some hit 300+ mg per can.

Pricing reality (mid-2026)

Pick this if…

• Default for most users: Cronometer + a sleep wearable.
• Caffeine-only, paid app: HeyMaja.
• Cheap / free / Apple-only: Apple Health caffeine + Sleep app.
• Whoop or Oura wearer: use the built-in caffeine log.
• Curious / nerdy: Pandas analysis on wearable + caffeine CSVs.
• Pregnancy / health condition: verify with your clinician; tracking helps; rules differ.