Coffee Data Lab · the authority engine

When the internet disagrees,
we run the numbers.

Flagship tool

The Caffeine Calculator · know your dose.

Every drink in our database sourced from lab analyses and manufacturer disclosures. Pick a drink, set your cups, see the mg, and how it stacks against the 400 mg guideline.

Open the calculator →
6

brew methods covered, ratio to water temperature, every number sourced

47

journal articles published, every claim cited to its source

6

drinks in the caffeine calculator, each with a sourced range

0%

scores influenced by brands or affiliates. Zero. Ever.

Data stories

Latest data stories.

A single roasted coffee bean shown in isolated close-up product-photo style against a plain white background, its center crease running vertically down the middle
Data22 Sept 2026 · 13 min read

How Much Caffeine Is Really in Decaf Coffee?

A 2006 lab test found Starbucks grande decaf at 12 to 13.4mg, about half the 25mg Starbucks itself lists. Here is what decaf actually contains.

A rustic brown ceramic mug filled with steaming black coffee on a dark wood table, dramatic side lighting emphasizing the rising steam
Data21 Sept 2026 · 12 min read

Coffee on an Empty Stomach: Benefits, Risks, and Why It Makes Some People Nauseous

An 8,000-person Japanese study found no ulcer link. Cleveland Clinic and Healthline agree on what coffee on an empty stomach actually does to you.

A plain white ceramic cup of black coffee sitting on a saucer, steam faintly visible above the surface
Data20 Sept 2026 · 12 min read

Is Coffee a Laxative? What the Evidence Actually Says

A 1990 study found only 29 percent of coffee drinkers feel the urge to go. A meta-analysis of 432,000 people found coffee actually lowers IBS risk overall.

A single roasted coffee bean shown in isolated close-up product-photo style against a plain white background, its center crease running vertically down the middle
Data17 Sept 2026 · 9 min read

How Much Caffeine Is in Tim Hortons Coffee? Every Size, By the Numbers

Tim Hortons published caffeine figures back in 2008: 140mg small to 330mg extra-large brewed coffee. Espresso and lattes split sharply by country, though.

A single roasted coffee bean shown in isolated close-up product-photo style against a plain white background, its center crease running vertically down the middle
Data14 Sept 2026 · 9 min read

How Much Caffeine Is in a K-Cup? The Real Range, By Size

Two independent trackers agree: a standard K-Cup runs 75 to 125mg of caffeine. The cup-size button changes dilution, not the fixed dose in the pod.

A single roasted coffee bean shown in isolated close-up product-photo style against a plain white background, its center crease running vertically down the middle
Data13 Sept 2026 · 11 min read

How Much Caffeine Is in Dunkin' Coffee? Every Size, By the Numbers

Dunkin' publishes an approximate caffeine range, unlike some chains. Two trackers confirm the size-by-size numbers: 180mg small to 330mg extra-large hot coffee.

Exhibit A: how much caffeine is in cold brew? Depends who you ask.

Starbucks Grande, in-store
43 mg
Starbucks bottled RTD
55 mg
High Brew Triple Shot
69 mg
Lab concentrate, max
123 mg

Same drink name, normalised to 100 ml, and the sourced answers still span 3x. Our data pages publish every source, the method behind it, and a reconciled range, so you can check every number yourself.