Quick Answer: The best overall caffeine tracker for iPhone is ARC, because it goes beyond passive cup-logging to calculate your live pharmacokinetic caffeine half-life decay curve and solves for your exact cutoff time to ensure you have under 50 mg in your system by bedtime. For standalone barcode scanning, HiCoffee is a strong secondary choice.
Most people drink coffee to boost energy during their morning and afternoon slumps. But caffeine has an average half-life of 5.5 hours (extending up to 7+ hours in slower metabolizers). If you finish an afternoon cold brew or energy drink, over half of that caffeine is still circulating when you lie down in bed, blocking adenosine receptors and sabotaging deep slow-wave sleep.
To help you protect your sleep architecture without quitting coffee, we tested and ranked the five best caffeine tracking apps for iOS in 2026.
2026 iPhone Caffeine Tracker Comparison Matrix#
| App | Annual / Lifetime Price | Live Half-Life Decay? | Bedtime Cutoff Calculator | Dynamic Island Widget | Apple Health Sync | Best For |
|---|---|---|---|---|---|---|
| ARC: Circadian Tracker | $39.99/yr | Yes (exact exponential) | Yes (under 50mg target) | Yes (Live Activity) | Yes | Circadian Sleep & Energy Optimization |
| HiCoffee | $11.99/yr ($29.99 lifetime) | Yes (basic model) | Fixed reminder | Lock Screen only | Yes | Standalone Caffeine Drink Logging |
| Waterllama | $3.99/mo ($39.99 lifetime) | Linear estimate | No | No | Yes | Fun Hydration & General Habit Tracking |
| Caffeine App (CaffCalc) | $1.99 one-time | Yes (formula) | Manual calculation | No | No | Minimalist Single-Metric Math |
| Apple Health | Free (Built-in) | No decay curve | None | No | Native | Raw Nutritional Data Storage |
1. ARC: Circadian Rhythm Tracker — Best Overall#
ARC is not just a caffeine log; it is an intelligent circadian rhythm operating system. Instead of simply recording how many milligrams you drank, ARC solves the equation backward from your target bedtime:
Key Features:
- Cumulative Pharmacokinetic Decay: Every drink you log—from an espresso to a Celsius (200mg) or Starbucks Cold Brew—stacks on top of your existing bloodstream baseline.
- Dynamic Bedtime Cutoff: ARC recalculates your "last safe cup" continuously throughout the day so that circulating caffeine falls below 50 mg before your head hits the pillow.
- Dynamic Island & Lock Screen Live Activity: Keep an eye on your active caffeine level and light-exposure windows without unlocking your phone.
- Holistic Circadian Protocol: Pairs caffeine timing with your biological chronotype (Lion, Bear, Wolf, or Dolphin) and morning sunlight timing.
- 100% On-Device Privacy: No cloud accounts, no third-party data tracking.
Price: $39.99/year (with 7-day free trial) or $4.99/week.
2. HiCoffee — Best Dedicated Caffeine Logger#
HiCoffee is one of the most dedicated standalone caffeine trackers in the Apple ecosystem. It features an extensive database of brand-name beverages and fast logging widgets for Apple Watch and iPhone.
- Pros: Excellent Apple Watch complications, support for custom drink presets, Siri Shortcuts integration.
- Cons: It treats caffeine in isolation. It does not synchronize with your circadian rhythm, does not time your morning light exposure, and lacks proactive schedule planning.
- Price: Free tier available; Pro is $11.99/year or $29.99 lifetime.
3. Waterllama — Best Gamified Hydration & Beverage App#
Waterllama is primarily a visual water-intake tracker that also supports caffeine and alcohol tracking with playful illustrated characters.
- Pros: Delightful UI, Apple Watch app, interactive streak tracking.
- Cons: Waterllama's caffeine decay modeling is rudimentary. It does not provide pharmacokinetic exponential half-life curves or bedtime clearance targets.
- Price: $3.99/month, $11.99/year, or $39.99 lifetime.
4. Caffeine App (CaffCalc) — Best Minimalist Utility#
Caffeine App is a straightforward tool designed for people who simply want to calculate how much caffeine is left after a set number of hours.
- Pros: Simple, fast, no subscription fees.
- Cons: Outdated interface, no automatic notifications, no Dynamic Island integration, and no daily chronotype schedule.
- Price: $1.99 one-time.
5. Apple Health (HealthKit) — Best Native Data Repository#
Apple Health includes a native "Caffeine" metric under Nutrition, allowing you to manually log milligrams or view data written by third-party apps like ARC and HiCoffee.
- Pros: Free, built into iOS, secure HealthKit storage.
- Cons: Purely a passive repository. Apple Health does not project decay curves, predict crashes, or alert you when your cutoff window arrives.
- Price: Free on iOS.
How to Choose the Right App for You#
- 1.If you want complete energy, light, and sleep alignment: Download ARC. It combines live caffeine pharmacokinetics with morning sunlight timing and chronotype-specific focus blocks.
- 2.If you only want a simple caffeine tally: Choose HiCoffee.
- 3.If your primary goal is drinking more water: Choose Waterllama.
Test your caffeine half-life right now with our free tools:
- Caffeine Half-Life & Cutoff Calculator
- Celsius 200mg Caffeine Clearance Table
- Starbucks Cold Brew Caffeine Clearance Table
- Daily Schedule Generator