How much caffeine is in Dr Pepper?

One 355 ml (12 fl oz) can of Dr Pepper contains 42 mg of caffeine.

Caffeine is a central nervous system stimulant that increases alertness and raises heart rate; this definition is provided here to clarify terminology. The 42 mg number is the measured caffeine content for a 355 ml serving in our dataset, reported as 11.8 mg per 100 ml and documented in the open dataset behind these pages (see our dataset for the source and measurement notes).

To put 42 mg in context, a standard 240 ml serving of drip coffee contains 96 mg of caffeine, per our reference data for drip coffee (240 ml = 96 mg) in the dataset, which means this Dr Pepper can is roughly 0.4× a cup of drip coffee when compared on milligrams of caffeine per serving, per the same dataset.

The concentration here (11.8 mg per 100 ml) matters because smaller or larger container sizes change the total dose linearly, and concentration is how technicians check for batch-to-batch differences during production; this concentration is stated in the dataset entry for this drink (our dataset), which is the canonical source for the mg values listed on this page.

Physically, a 42 mg dose often produces mild stimulant effects (increased alertness, small rise in heart rate) for many adults, but subjective effects vary and depend on body size, habitual use, and individual sensitivity, as clinical guidance on caffeine intake notes (see the U.S. Food and Drug Administration guidance on daily limits linked in the sourcing section).

How long Dr Pepper stays in your system

Half-life is the time required for the body to eliminate half of a drug; for caffeine, a commonly used population-average half-life is 5.7 hours, with that value coming from clinical summaries of caffeine metabolism and guidance on sleep and timing (Mayo Clinic), which we use for the decay model shown here.

We model elimination as first-order (meaning a constant fraction is removed per unit time) with the formula: remaining = dose × 0.5^(hours / 5.7); first-order elimination is a pharmacokinetic description meaning decline follows an exponential curve rather than a fixed mg-per-hour drop. For this 42 mg dose the arithmetic is:

3 hours: remaining = 42 × 0.5^(3 / 5.7) = 42 × 0.695 ≈ 29.2 mg, reported here as ~29 mg (model and half-life from Mayo Clinic).

6 hours: remaining = 42 × 0.5^(6 / 5.7) = 42 × 0.482 ≈ 20.3 mg, reported here as ~20 mg (model and half-life from Mayo Clinic).

9 hours: remaining = 42 × 0.5^(9 / 5.7) = 42 × 0.335 ≈ 14.1 mg, reported here as ~14 mg (model and half-life from Mayo Clinic).

12 hours: remaining = 42 × 0.5^(12 / 5.7) = 42 × 0.232 ≈ 9.7 mg, reported here as ~10 mg (model and half-life from Mayo Clinic).

As an example of practical timing: if the can is finished at 15:00, the model predicts about 20 mg still present at 21:00 and about 10 mg at 03:00 the next day, using the 5.7-hour half-life cited above (Mayo Clinic), which helps explain why late-evening soda can still affect sleep for some people.

The U.S. Food and Drug Administration recommends a guidance limit of 400 mg of caffeine per day for healthy adults, and using that guidance a single 355 ml can of Dr Pepper contributes 11% of the 400 mg recommendation (42 mg is 11% of 400 mg, guidance: FDA).

To estimate a safe last serving before a 23:00 bedtime using the half-life model above and the 5.7-hour population half-life (Mayo Clinic), the remaining caffeine at 23:00 from a 15:00 can would be about 20 mg at 21:00 and about 10 mg at 03:00 the next day, so finishing a can at 21:00 leaves more residual caffeine at 23:00 than finishing the same can earlier; the half-life arithmetic and model come from the Mayo Clinic summary used for the elimination parameter (Mayo Clinic).

Certain populations should use a lower benchmark than 400 mg: the European Food Safety Authority recommends a maximum single dose of 200 mg and 200 mg per day for pregnant women, per EFSA's 2015 scientific opinion, so a 42 mg can would be a much smaller fraction under those pregnancy-specific limits (EFSA 2015: EFSA).

Adolescents and people with caffeine sensitivity or certain medical conditions metabolize caffeine differently and may be advised to limit intake; our safe daily limit by body weight tool and the last-cup-before-bed calculator can help turn a 42 mg figure into personalized timing or dose guidance using body weight and bedtime inputs.

Within sodas, this 355 ml Dr Pepper at 42 mg sits near the middle of the range captured in our data: for comparison, Coca-Cola (330 ml) is 32 mg and Coca-Cola (355 ml) is 34 mg, Diet Coke (355 ml) is 46 mg, Pepsi (355 ml) is 38 mg, and Mountain Dew (355 ml) is 54 mg, with all of those figures taken from the same open dataset that supplies this page's numbers (dataset).

Against coffee, the difference is clear in absolute dose: a 240 ml cup of drip coffee in our reference contains 96 mg of caffeine, per our dataset, which is roughly 2.3× the caffeine in a 355 ml can of Dr Pepper (96 mg per 240 ml for drip coffee vs. 42 mg per 355 ml for this soda, dataset source: dataset).

Viewed another way, an energy drink like Red Bull (250 ml = 80 mg) or a Monster Energy (473 ml = 160 mg) supplies substantially more caffeine than this soda, with those energy drink values recorded in our dataset (Red Bull 250 ml = 80 mg, Monster 473 ml = 160 mg, dataset: dataset), which is why people tracking stimulant intake often compare cans and coffee side-by-side using a tool such as our caffeine comparison page to see cumulative totals.

What changes the number for Dr Pepper

The 42 mg figure is specific to the 355 ml (12 fl oz) serving listed in the dataset; that value comes from measured or manufacturer-declared figures compiled into our open dataset (dataset), and the actual caffeine in any particular can can vary because of manufacturing tolerances and regional formula differences, per the notes collected in the same dataset.

Size is the primary driver of total caffeine: concentration (11.8 mg per 100 ml) multiplied by volume gives total mg, so a larger bottle increases the dose proportionately; this arithmetic follows directly from the concentration reported in the dataset entry for this drink (dataset).

Composition and variant change the number as well: cola recipes, diet formulations, and “zero” sugar versions sometimes differ in caffeine content, and the dataset shows neighboring sodas with different mg values (for example, Coca-Cola 355 ml = 34 mg, Diet Coke 355 ml = 46 mg, and Coke Zero 355 ml = 34 mg), with those numbers recorded in the open dataset and viewable on the corresponding product pages (Coca-Cola (355 ml) and Coca-Cola Diet Coke, dataset entry cited in each product page).

Batch-to-batch variation and testing method are additional sources of uncertainty: laboratory assays (HPLC, mass spectrometry) and manufacturer labelling differ in precision, which is why the dataset compiles published values rather than claiming a single immutable number; the dataset page explains measurement methods and uncertainty (dataset).

• Decaffeinated or intentionally caffeine-free alternatives exist; our value of 42 mg applies only to the standard caffeinated Dr Pepper entry in the dataset (dataset).

Because of these factors the 42 mg figure should be treated as the best available estimate from published sources rather than an exact constant for every can produced on every date, as explained in our dataset documentation (dataset).

Where this figure comes from

The 42 mg value on this page is taken from the open caffeine dataset that aggregates manufacturer declarations, government databases, and lab analyses; the dataset entry and measurement notes are available at /dataset/, and where the dataset cites a government source we link those sources directly in the dataset details (dataset entry for this drink is the primary source for the 42 mg value).

Published values disagree for three main reasons: different serving sizes, lab method and detection limits, and regional recipe differences; when manufacturer labels and independent assays differ we record both where available and explain the discrepancy on the dataset page (dataset), and we will update this page if authoritative new measurements (for example, USDA FoodData Central entries or manufacturer lab results) change the canonical figure.

Bottom line

Bottom line: a standard 355 ml can of Dr Pepper contains 42 mg of caffeine (11.8 mg per 100 ml) according to the open dataset entry for this drink (dataset), which is about 0.4× a 240 ml cup of drip coffee (96 mg per 240 ml, dataset), and it accounts for 11% of the 400 mg/day guidance from the U.S. Food and Drug Administration (FDA). The population-average elimination model with a 5.7-hour half-life (Mayo Clinic) predicts ~29 mg remaining at 3 hours, ~20 mg at 6 hours, ~14 mg at 9 hours, and ~10 mg at 12 hours after drinking this can (Mayo Clinic).