Data study
How much caffeine is in a cup of coffee?
By Paul Tanswell · Data checked 2026-10-02
Barista Bench data · caffeine
USDA's reference figure for a cup of brewed coffee is
95mg
of caffeine per 8 fl oz (237 ml). Real cups spread much wider: 14 retail filter coffees bought in the UK and tested in one study (UK Food Standards Agency, 2004) ranged from 21 to 208 mg at the same cup size.
Key findings
- USDA's reference figure for an 8 fl oz (237 ml) cup of brewed coffee is 95 mg of caffeine, but 14 retail filter coffees bought in the UK and tested in one study (UK Food Standards Agency, 2004) ranged from 21 to 208 mg at that cup size.
- 124 single espressos bought in cafes in Glasgow, Parma and Pamplona measured 51 to 322 mg of caffeine per shot as served, with a median of 108 mg; 122 of them were above USDA's 64 mg for a 30 ml (1 fl oz) shot.
- 14 retail filter coffees bought in the UK and tested in one study (UK Food Standards Agency, 2004) had a median of 103 mg per 8 fl oz (237 ml); the measured median for a single espresso, per shot as served, is 108 mg (124 shots).
- Starbucks declares 155 mg for its Short Pike Place Roast, 8 fl oz (237 ml), and 390 mg for the Venti Pike Place Roast, 20 fl oz (591 ml); its single espresso shot, 0.75 fl oz (22 ml), is declared at 75 mg.
| Drink | Serving | Figure | Range | Basis |
|---|---|---|---|---|
| Espresso, single shot | As served, 13 to 104 ml (0.4 to 3.5 fl oz) | 108 mg median | 51 to 322 mg | 124 servings, 2 studies; USDA reference 64 mg |
| Espresso, double shot | As served, 22 to 23 ml (0.7 to 0.8 fl oz) | 165 mg median | 152 to 174 mg | 3 servings, 1 study, made in a lab, not bought |
| Brewed (drip) coffee | 237 ml (8 fl oz) | 103 mg median | 21 to 208 mg | 14 servings, 1 study; USDA reference 95 mg |
| Instant coffee | 237 ml (8 fl oz) | 90 mg median | 31 to 167 mg | 16 servings, 2 studies |
| Decaf, brewed | 237 ml (8 fl oz) | 5 mg median | 5 mg | 1 serving, 1 study |
| Black tea, brewed | 237 ml (8 fl oz) | 47 mg declared | 47 mg | USDA reference |
| Green tea, brewed | 237 ml (8 fl oz) | 28 mg declared | 28 mg | USDA reference |
| Cola | 355 ml (12 fl oz) | 33 mg declared | 33 mg | USDA reference |
| Red Bull | 248 ml (8.4 fl oz) | 80 mg declared | 80 mg | declared by maker |
| Monster Energy | 473 ml (16 fl oz) | 160 mg declared | 160 mg | declared by maker |
| Celsius | 355 ml (12 fl oz) | 200 mg declared | 200 mg | declared by maker |
Why caffeine in coffee is a range, not a number
The same order from the same cafe does not come out the same twice. Ludwig and colleagues (2014) bought espresso from each outlet on four occasions; at one Glasgow cafe, University Cafe, the four shots measured 180 to 276 mg. McCusker and colleagues (2003) report the same thing for brewed coffee in the US: one outlet's coffee, bought on six days, measured 259 to 564 mg per 16 fl oz (473 ml) cup (from the paper's abstract).
Where you buy it matters too. In the same study, Glasgow shots ranged from 66 to 276 mg, against 54 to 150 mg in Parma and 82 to 139 mg in Pamplona. The outlets also used different amounts of coffee per shot: 5 to 8 g in Parma, 9 g in Pamplona and 9 to 18 g in Glasgow.
Serving size is the plainest cause. The measured single espressos ran from 13 to 104 ml (0.4 to 3.5 fl oz) as served. Starbucks sells Pike Place Roast from 8 to 20 fl oz (237 to 591 ml) and declares 155 to 390 mg across those sizes. The filter coffees in the UK Food Standards Agency's 2004 survey were made up by the customer or an employee, and some may have had milk added, which lowers the figure per ml.
Roast does less than most people think. Lindsey and colleagues (Scientific Reports, 2024) brewed two Ethiopian coffees at five roast levels, always from the same 10 g of ground coffee. Across every roast and brew time the cups came out at 134 to 165 mg per 8 fl oz (237 ml) for one coffee and 145 to 165 mg for the other. Roast moved caffeine by only a few percent, and not in one direction; how fully the coffee was extracted mattered more. The study weighed its coffee and did not test scoops, so it does not say whether a scoop of dark roast holds less caffeine than a scoop of light.
Starbucks coffee and espresso caffeine
| Drink | Serving | Caffeine | Source | Checked |
|---|---|---|---|---|
| Espresso, Solo | 22 ml (0.75 fl oz) | 75 mg (declared) | Starbucks Coffee Company. Espresso, product 410, nutrition by size. | 2026-10-02 |
| Espresso, Doppio | 44 ml (1.5 fl oz) | 150 mg (declared) | Starbucks Coffee Company. Espresso, product 410, nutrition by size. | 2026-10-02 |
| Pike Place Roast, Short | 237 ml (8 fl oz) | 155 mg (declared) | Starbucks Coffee Company. Medium Roast, Pike Place Roast, product 480, nutrition by size. | 2026-10-02 |
| Pike Place Roast, Tall | 355 ml (12 fl oz) | 235 mg (declared) | Starbucks Coffee Company. Medium Roast, Pike Place Roast, product 480, nutrition by size. | 2026-10-02 |
| Pike Place Roast, Grande | 473 ml (16 fl oz) | 315 mg (declared) | Starbucks Coffee Company. Medium Roast, Pike Place Roast, product 480, nutrition by size. | 2026-10-02 |
| Pike Place Roast, Venti | 591 ml (20 fl oz) | 390 mg (declared) | Starbucks Coffee Company. Medium Roast, Pike Place Roast, product 480, nutrition by size. | 2026-10-02 |
We also checked Dunkin' and McDonald's. Dunkin' publishes caffeine figures but no volumes for its hot coffee or espresso, and McDonald's keeps its caffeine values hidden on its US site, so neither has a table here.
Beyond coffee
| Drink | Caffeine | Source | Checked |
|---|---|---|---|
| Dark chocolate, 28 g (1 oz) | 22 mg (declared) | USDA FoodData Central. Chocolate, dark, 70-85% cacao solids. SR Legacy, FDC ID 170273. | 2026-10-02 |
| Pre-workout, one scoop | 200 mg (declared) | Cellucor. C4 Original Pre-Workout Powder, product page. | 2026-10-02 |
| Caffeine pill, one caplet | 200 mg (declared) | NoDoz. Drug Facts label, NoDoz caplets. | 2026-10-02 |
How much caffeine is too much?
EFSA found that habitual intake up to 400 mg a day, about 5.7 mg per kg of body weight, raises no safety concern for healthy adults who are not pregnant. Single doses up to 200 mg, about 3 mg per kg, raise none either. During pregnancy its figure is 200 mg a day. It also found that a single 100 mg dose may affect sleep when taken close to bedtime. The US FDA has cited 400 mg a day as an amount not generally associated with negative effects for most adults.
| Situation | What EFSA found |
|---|---|
| Single dose | Up to 200 mg (about 3 mg per kg) raises no safety concern |
| Per day, healthy adults who are not pregnant | Up to 400 mg (about 5.7 mg per kg) raises no safety concern |
| Per day in pregnancy | Up to 200 mg raises no safety concern for the foetus |
| Close to bedtime | A single 100 mg dose may affect sleep |
This page summarises published research and is not medical advice. Sources: EFSA, 2015; FDA, 2024.
Questions
How much caffeine is in a cup of coffee?
USDA's reference figure for brewed coffee is 95 mg per 8 fl oz (237 ml) cup. Real cups vary far more than one number suggests: 14 retail filter coffees bought in the UK and tested in one study (UK Food Standards Agency, 2004) ranged from 21 to 208 mg when scaled to the same cup size. Starbucks declares 155 mg for its Short Pike Place Roast, 8 fl oz (237 ml).
How much caffeine is in a shot of espresso?
The median of 124 single espressos bought in cafes and measured in a lab is 108 mg, and the shots ranged from 51 to 322 mg. Both studies behind that figure (Crozier et al., 2012; Ludwig et al., 2014) come from one Glasgow research group. USDA's reference figure is 64 mg per 30 ml (1 fl oz).
Does espresso have more caffeine than coffee?
Per ml, espresso is far stronger; per drink, it depends on the cup and the shot. 14 retail filter coffees bought in the UK and tested in one study (UK Food Standards Agency, 2004) had a median of 103 mg per 8 fl oz (237 ml); the measured median for a single espresso, per shot as served, is 108 mg (124 shots). The cup figure rests on one survey, so treat the comparison as rough.
How much caffeine is in instant coffee?
16 instant coffees measured in 2 studies (Ludwig et al., 2014; UK Food Standards Agency, 2004), scaled to an 8 fl oz (237 ml) cup, had a median of 90 mg and ranged from 31 to 167 mg.
How much caffeine is in decaf coffee?
The one decaf filter coffee in the UK Food Standards Agency's 2004 survey measured 5 mg per 8 fl oz (237 ml). Decaf is low in caffeine, not free of it.
How much caffeine is too much?
EFSA found that up to 400 mg a day raises no safety concern for healthy adults who are not pregnant, and single doses up to 200 mg raise none. During pregnancy its figure is 200 mg a day. The US FDA has cited 400 mg a day as an amount not generally associated with negative effects for most adults.
Espresso caffeine, shot by shot · Methodology and every source