Caffeine guides

What are these guides for and who writes them?

These guides are practical, data-driven explanations that answer common questions about how much caffeine is in a drink, what that amount does in the body, and practical steps readers can take; the first two sentences answer the question fully. The guides are written by the TrackCaffeine editorial team using an open dataset and a simple pharmacokinetic model; see the site method at /about/ for authorship and methods.

Dataset is an open collection of drink caffeine values available at /dataset/, and the whole dataset is published under a CC BY 4.0 licence at CC BY 4.0 to allow reuse.

The TrackCaffeine model is public and described on /about/; the model uses a population-average half-life of 5.7 hours (342 minutes) and first-order elimination, which lets readers run consistent calculations across drinks.

First-order elimination is a process where the rate of elimination is proportional to the current amount in the body; this is the pharmacokinetic assumption behind our calculator and is stated on /about/.

Half-life is the time it takes for the substance amount to fall by half; our population-average half-life is 5.7 hours (342 minutes) and that number appears in the model documentation at /about/.

Every guide links back to the original numeric entries in the dataset, so if you want the source for a specific milligram value you can check the dataset entry such as Espresso (single), 63 mg or Cold brew, 200 mg and the dataset page at /dataset/ provides provenance and licensing.

How do caffeine questions cluster: how much is in X, how long does it last, is this amount safe, how do I stop or cut down, and what does it do to sleep and to exercise?

Most visitor questions fall into clear clusters: "How much is in X?", "How long will it last?", "Is this amount safe for me?", "How do I stop or cut down?", and "What does this dose do to sleep or exercise?" The rest of this section explains each cluster and points to the relevant guides and tools.

When people ask "How much is in X?" they are asking for a measured milligram value that we quote from the dataset entry; for example, 5 Hour Energy: Complete Caffeine Content Guide uses the dataset value 200 mg for 5-Hour Energy and cites the dataset at /dataset/.

When the question is "How long does it last?" we use the first-order elimination model with population-average half-life 5.7 hours (342 minutes) to estimate remaining caffeine; the formula is remaining = dose × 0.5^(hours ÷ 5.7), and the model and calculator are available at /tools/caffeine-calculator/ and described on /about/.

Example arithmetic using the model: a Starbucks Pike Place Brewed (Grande) contains 310 mg (source: dataset entry and /dataset/); after 6 hours remaining = 310 mg × 0.5^(6 ÷ 5.7) = 310 mg × 0.5^(1.0526) = 310 mg × 0.4822 ≈ 149.5 mg, calculated with the model described on /about/.

Safety questions often ask if a given intake is within recommended daily limits; a commonly cited limit is 400 mg/day for healthy adults, as noted on the FDA page that states 400 mg/day for healthy adults (source: FDA).

For step-down or quitting questions the practical resources include timing and withdrawal guides such as Caffeine Withdrawal: Symptoms, Duration, and Management and alternatives like Best Caffeine-Free Coffee Options, and you can use the safe daily limit by body weight tool to plan a taper.

Exercise and performance questions are covered in guides such as Caffeine in Pre-Workout: Dosage, Timing, and Benefits, and those guides reference typical pre-workout doses from the dataset like Pre-workout (1 scoop) 200 mg (source: dataset entry and /dataset/).

Sleep-specific questions are often about timing; Drake et al. 2013 found that a 400 mg dose given six hours before bedtime reduced total sleep time by over one hour (source: Drake et al. 2013), a result we link to from our sleep timing calculator at /tools/last-cup-before-bed.

What does the evidence actually support versus what gets repeated online?

The evidence supports dose-dependent effects on alertness, heart rate variability in some settings, and sleep disruption at doses hundreds of milligrams before bedtime; the site links those claims to primary sources such as EFSA (2015) for safety opinions and Drake et al. 2013 for sleep timing effects (sources: EFSA 2015; Drake et al. 2013).

What gets repeated online without consistent evidence includes precise individual tolerance claims, anecdotal narrow windows of safety, or the idea that any single serving is categorically 'safe' for everyone; instead, the evidence usually reports population-level effects and uncertainty intervals, such as EFSA's assessment in 2015 (source: EFSA Scientific Opinion, 2015).

Citing an authoritative figure: the FDA's consumer guidance mentions 400 mg/day as a reference level for healthy adults (source: FDA), and we present that number as a limit rather than a guarantee of safety for every individual.

A practical caveat is that beverages with the same label can vary by preparation and serving size; the dataset shows, for example, Drip coffee 96 mg per 240 ml and Pour over 145 mg per 240 ml (sources: drip coffee, pour over, and /dataset/), demonstrating method-dependent variation.

For readers who have read an impressive-sounding claim online, we recommend checking the corresponding dataset entry and the relevant guide such as Black Coffee: Health Benefits and Potential Risks or the measurement guidance in Caffeine in Coffee: A Comprehensive Measurement Guide, and then using the calculators at /tools/ to see the numbers for your timing and dose.

How do we handle the difference between a manufacturer figure and a measured one?

We list the figure provided by a manufacturer when available and compare it to measurements and independent reports when they exist; the comparison is done visibly in each guide and each numeric entry links back to its dataset source at /dataset/.

Manufacturer figure is the value declared by the product maker on packaging or official nutrition information; measured value is the result of chemical analysis or a consistent independent test and both types of figures are represented in our dataset entries where applicable (source: /dataset/ and licence CC BY 4.0).

We flag discrepancies so readers can see when a product label claims one number and testing finds another; for example, label claims for some energy shots match the dataset entry for 5-Hour Energy at 200 mg (source: 5 Hour Energy: Complete Caffeine Content Guide and /dataset/), but we also highlight when measured values in the literature differ from a manufacturer's stated number.

When only a manufacturer figure exists we label it clearly as declared and add a caveat about preparation and serving size variability; the dataset includes many declared values such as Bang 300 mg per 473 ml (source: Bang and /dataset/), and guides explain the implications of using a declared number for timing and safety calculations.

For users who need precision for timing, we recommend using the brand's stated dose only as an input to the half-life model and, where possible, verifying with a measured figure; the calculators at /tools/caffeine-calculator/ and /tools/last-cup-before-bed/ accept any milligram value you enter and apply the population half-life of 5.7 hours (342 minutes) described on /about/.

Where should I start depending on what I came for?

If you came to find "how much is in my drink" start with the drink index at /caffeine-in/ or the specific guide for that product, for example Bang Energy Drink: Exactly How Much Caffeine is Inside? which cites Bang at 300 mg per 473 ml in the dataset (source: /dataset/ and the guide).

If you came to understand "how long will it last" run the number through our half-life calculator at /tools/caffeine-calculator/ or use the site formula remaining = dose × 0.5^(hours ÷ 5.7); for example, Cold brew 200 mg (source: dataset entry and /dataset/) after 8 hours is remaining = 200 mg × 0.5^(8 ÷ 5.7) = 200 mg × 0.5^(1.4035) = 200 mg × 0.3778 ≈ 75.6 mg using the population half-life 5.7 hours described on /about/.

If you came to check safety limits start with the safety guide at How Much Caffeine is Safe? Daily Intake Guidelines and the FDA reference of 400 mg/day for healthy adults (source: FDA), and use /tools/safe-daily-limit/ to compare your planned intake to that limit.

If you came to reduce or stop, read Caffeine Withdrawal: Symptoms, Duration, and Management and plan a taper using the per-serving values in the dataset such as Espresso (single) 63 mg or Latte 68 mg (sources: Espresso (single), 63 mg, Latte, 68 mg, and /dataset/), and consider caffeine-free swaps listed in Best Caffeine-Free Coffee Options.

If you came for sleep or exercise guidance use the sleep timing calculator at /tools/last-cup-before-bed/ and the pre-workout guide at Caffeine in Pre-Workout; Drake et al. 2013 provides a concrete sleep timing result showing 400 mg six hours before bedtime reduced sleep by over an hour (source: Drake et al. 2013), and EFSA (2015) summarizes wider safety considerations (source: EFSA 2015).

If you prefer a quick comparison between two drinks use /tools/caffeine-comparison/; for example, compare Espresso (double) 126 mg (source: dataset entry) to Nitro cold brew 215 mg per 240 ml (source: dataset entry and /dataset/), then run the remaining calculations in the half-life calculator at /tools/caffeine-calculator/.

Finally, if you want to browse curated reading rather than numbers, the guides include thematic pieces such as Black Coffee vs Green Tea: Which is Healthier?, Chocolate and Caffeine: How Much is in Your Treat?, and rankings like Top Energy Drinks: Ranking by Caffeine Content, each of which links to the underlying dataset values at /dataset/ for readers who want to see the milligrams and provenance.

If you want to correct or question a number use /contacts/ for corrections and the dataset page at /dataset/ for provenance; the dataset and our method aim for transparency so readers can check every numeric claim back to its source and licence information at CC BY 4.0.

As a small editorial note, a third-party tracker called CoffeeLog is occasionally cited by readers and is referenced sparingly and only once here to acknowledge that multiple independent compilations exist, but our guides prefer the dataset and the calculators on this site as the canonical starting points (source: /dataset/ and /about/).