Caffeine comparison: put two drinks side by side

Total caffeine vs concentration

Two numbers decide how a drink hits you: the total caffeine in the serving and the concentration per 100 ml. A 473 ml Monster (160 mg) has twice the total of a 250 ml Red Bull (80 mg), yet their concentration is almost identical at about 32–34 mg per 100 ml — the Monster is simply a bigger pour. Concentration is the fair way to compare a soda (around 10 mg/100 ml) against an espresso (over 200 mg/100 ml), while total mg is what matters for your daily limit.

The decay tail most comparisons ignore

Caffeine clears with a half-life near 5.7 hours, so the gap between two drinks shrinks over time but never reverses. A 300 mg pre-workout still leaves about 144 mg after 6 hours and 69 mg after 12; an 80 mg Red Bull is down to roughly 38 mg and 18 mg over the same window. If you are comparing drinks for an afternoon lift, the 6- and 12-hour columns tell you which one is more likely to still be working at bedtime.

Make the comparison personal

Equivalence in cups of coffee is the most intuitive frame: divide the caffeine by 96 mg, the amount in a standard 240 ml cup. A Bang (300 mg) is about three coffees in one can. Once you know the equivalents, logging them is easy — CoffeeLog stores all of these drinks so a tap records the exact milligrams and adds them to your day.

Which comparison is the most useful — per serving, per 100 ml, or per dollar?

Per serving answers "how much caffeine am I getting right now" and per 100 ml answers "how concentrated is the drink," so use per serving for dose decisions and per 100 ml for strength-by-volume decisions. Per dollar is a purchasing metric useful for budgeting but it often mixes size and concentration and therefore misleads about physiological effect.

Concentration is the caffeine per 100 ml of drink, expressed as mg per 100 ml, and total caffeine is the absolute milligrams in the serving. Concentration is a measure of intensity per sip and total caffeine is a measure of dose over the whole serving.

Per-serving comparisons are the correct choice when you need to track intake against a daily limit or a planned stimulant dose: for example, a single espresso is 63 mg per 30 ml and drip coffee is 96 mg per 240 ml in our dataset, so a single espresso delivers 63 mg and one cup of drip delivers 96 mg (see the individual entries for Espresso (single) and Drip coffee). Every per-serving number in the dataset is the number you add to a daily tally or to a calculator such as /tools/safe-daily-limit/ or /tools/caffeine-calculator/.

Per-100 ml comparisons are the correct choice when comparing how "strong" a drink tastes or how much caffeine you get per swallow: for example, cold brew is 83.3 mg/100 ml and drip coffee is 40 mg/100 ml in the dataset, so cold brew is more concentrated per sip (see Cold brew and Drip coffee). Use concentration when you care about strength-per-volume, such as choosing a small but highly concentrated espresso versus a large, weak soda.

Per-dollar comparisons are useful for cost-efficiency, not for physiology; per-dollar comparisons mix price, volume and concentration and can make a large, weak drink appear better just because it costs less per mg of caffeine. If you need to budget caffeine across many days, compute mg per cost separately from mg per serving so you do not conflate dose with expense.

Which of the common comparisons people search for are decisive: espresso versus drip, energy drink versus coffee, green tea versus black tea, cold brew versus iced coffee, and matcha versus coffee?

Espresso versus drip: a single espresso is 63 mg per 30 ml and a standard cup of drip coffee is 96 mg per 240 ml, so drip coffee gives a larger total dose while espresso gives a far higher concentration per sip. The dataset shows Espresso (single) 63 mg and Drip coffee 96 mg, and the espresso shot concentrates 63 mg into 30 ml (63 mg ÷ 30 ml × 100 = 210 mg/100 ml).

Energy drink versus coffee: energy cans range from moderate to very high totals in the dataset — for example, Red Bull (250 ml) is 80 mg and Bang (473 ml) is 300 mg — while brewed coffee examples range similarly or higher for shop pours; compare Red Bull (250 ml) 80 mg, Bang 300 mg and Drip coffee 96 mg. Which is "more caffeine" depends on the specific product, so check the per-serving numbers in our dataset before equating the entire category of "energy drink" with "coffee."

Green tea versus black tea: black tea is higher in total caffeine per serving in the dataset — Black tea is 47 mg per 240 ml and Green tea is 28 mg per 240 ml — so a cup of black tea delivers roughly 47 mg compared with 28 mg from green tea, as listed at Black tea and Green tea. Use these per-serving numbers when you are comparing swaps: replacing a black tea with a green tea will lower your intake by about 19 mg per cup in our dataset.

Cold brew versus iced coffee (brewed coffee served cold): cold brew is far more concentrated by volume in our dataset, with Cold brew 200 mg per 240 ml (83.3 mg/100 ml) versus drip coffee 96 mg per 240 ml (40 mg/100 ml), so cold brew gives roughly twice the caffeine per same-sized serving; see Cold brew and Drip coffee. If a shop serves brewed coffee over ice without diluting, that iced coffee will deliver a dose closer to the brewed value, but if they use cold brew concentrate or a larger shot count the per-serving total will be higher.

Matcha versus coffee: Matcha (1 tsp) is 70 mg per 240 ml in our dataset and a standard cup of drip coffee is 96 mg per 240 ml, so a single teaspoon of matcha gives less caffeine than a cup of drip coffee but more than a typical green tea infusion; see Matcha (1 tsp) and Drip coffee. Compare per-serving totals when you care about the absolute dose and per-100 ml when you care about sip strength.

Why are "stronger" and "more caffeine" different claims?

"Stronger" describes concentration and "more caffeine" describes total dose; they are different claims because concentration is mg per 100 ml while total caffeine is the milligrams in the serving. Strength is concentration per 100 ml, and total caffeine is the mg in the whole serving, so a small, concentrated espresso can be stronger yet contain less total caffeine than a large cup of brewed coffee.

Example: Espresso (single) is 63 mg in 30 ml, which is 63 mg ÷ 30 ml × 100 = 210 mg/100 ml (see Espresso (single)), while drip coffee is 96 mg in 240 ml, which the dataset gives as 40 mg/100 ml (see Drip coffee). The espresso is stronger by concentration (210 mg/100 ml vs 40 mg/100 ml) but smaller in total dose (63 mg vs 96 mg). This difference matters when you choose a drink to avoid adding to your daily total versus when you choose a drink to get a strong sip sensation.

Caveat: shops alter both concentration and serving size; for example, Starbucks Blonde Espresso (shot) is 85 mg in 30 ml in the dataset, which changes the comparison against shop pours such as Starbucks Pike Place Brewed (Grande) 310 mg in 473 ml. Always compare the specific product's per-serving and per-100 ml numbers rather than relying on category labels.

How should I compare two drinks for a bedtime decision rather than for a caffeine total?

For bedtime decisions compare the expected remaining caffeine at your bedtime using first-order elimination with a population-average half-life of 5.7 hours; that remaining amount predicts sleep impact better than the initial total. Half-life is the time it takes for the body to eliminate half of the caffeine present, and our model uses half-life = 5.7 hours (342 minutes) to estimate remaining caffeine with the formula: remaining = dose × 0.5^(hours ÷ 5.7).

Example 1: If you drink Starbucks Cold Brew (Grande) 205 mg and go to bed 6 hours later, the remaining caffeine is 205 × 0.5^(6 ÷ 5.7) = 205 × 0.482 ≈ 99 mg (see Starbucks Cold Brew (Grande)). That arithmetic shows how a large earlier dose can still leave a substantive mg at bedtime.

Example 2: If you drink an Espresso (double) 126 mg and sleep 6 hours later, the remaining caffeine is 126 × 0.5^(6 ÷ 5.7) = 126 × 0.482 ≈ 61 mg (see Espresso (double)). In this example the espresso started smaller and leaves less remaining caffeine at bedtime than the Cold Brew example above, despite its higher concentration.

Example 3: A Bang 300 mg consumed 6 hours before bed leaves 300 × 0.5^(6 ÷ 5.7) = 300 × 0.482 ≈ 145 mg remaining, which is substantially higher than the brewed-coffee and espresso examples (see Bang). Use these remaining-mg calculations to compare sleep risk across two drinks rather than starting totals.

Caveat and evidence: large doses shortly before bed cost sleep — the dataset calculator assumptions mirror published sleep effects such as Drake et al. 2013, which reported that 400 mg six hours before bed cost over an hour of sleep (Drake et al. 2013). For reference on recommended daily limits, the FDA cites 400 mg per day for healthy adults (FDA). Use /tools/last-cup-before-bed/ for a tailored bedtime cutoff and /tools/caffeine-calculator/ to compute remaining caffeine for your schedule.

How the comparison tool extends these judgments and when it can mislead

The side-by-side comparison tool reports both per-serving totals and per-100 ml concentrations, and it shows remaining caffeine at chosen intervals using the 5.7-hour half-life so you can make both dose and bedtime comparisons in one view. The tool is designed to produce the two most relevant numbers—total mg for intake tracking and mg/100 ml for sip strength—along with remaining-mg columns to support timing decisions.

When the tool misleads: it can mislead if you compare different serving sizes without normalizing for volume, if you ignore milk or food that can slow absorption, or if you assume the population-average half-life applies to everyone; for example, Latte and Latte (large, 2 shots) in the dataset have the same or similar total mg depending on shot count but different volumes, which changes per-100 ml comparisons. Biological variation, pregnancy, medications and liver function change half-life and are not reflected in the population-average model.

Practical tip: when in doubt about a bedtime decision use the remaining-mg comparison from the tool rather than the starting mg; if you want a quick rule of thumb, compare the remaining mg of two choices at the bedtime interval you care about and pick the one with the lower remaining mg. You can verify numbers by opening the drink pages such as Cold brew, Nitro cold brew, Dunkin' Cold Brew (Medium), Drip coffee, Espresso (double), Matcha (1 tsp), Green tea and Black tea in the dataset to confirm per-serving numbers.

Data licensing and provenance: our numbers come from the open dataset licensed under CC BY 4.0 (CC BY 4.0) and are compiled with references to laboratory and manufacturer lists when available; consult /dataset/ and /about/ for the full method and sources. If you see an error, submit a correction via /contacts/.

How to use the comparison tool together with the other calculators on this site?

Start with the side-by-side tool to choose drinks and view per-serving and per-100 ml numbers, then click "calculate remaining" to send those totals to the half-life calculator for precise timing analysis. The three companion tools are /tools/caffeine-calculator/, /tools/last-cup-before-bed/ and /tools/safe-daily-limit/, which together let you estimate remaining mg, the latest safe cup before sleep, and a body-weight-adjusted daily limit.

Practical workflow: if you are planning an afternoon workout use the comparison tool to pick a pre-workout or coffee, then paste the chosen drink's mg into /tools/caffeine-calculator/ to see remaining mg at the time you expect to sleep; if you want to know how that intake relates to a safe daily limit, open /tools/safe-daily-limit/ and compare the planned total to recommended limits. For logging and long-term tracking you can note the per-serving totals from the comparison and store them in an app such as CoffeeLog or a spreadsheet for daily sums.

Caveat: these calculators use a population-average half-life and fixed per-serving numbers; individual metabolism and shop churn mean model outputs are estimates, not guarantees. For authoritative safety thresholds use published guidance: the FDA states 400 mg per day for healthy adults (FDA) and the EFSA scientific opinion provides detailed safety analysis (EFSA Scientific Opinion on the Safety of Caffeine, 2015).