How much caffeine is in an espresso?

A standard 30 ml espresso averages 60 to 80 mg of caffeine, with the USDA reference value around 63 mg. Specialty shots, pulled with a heavier 18-20 g dose, commonly land between 100 and 150 mg. That is often less caffeine than a 200 ml filter-coffee mug, which easily carries 150-200 mg.

How much caffeine ends up in your espresso depends on four levers: variety (Arabica or Robusta), ground-coffee dose, water volume pushed through the puck, and extraction time. USDA FoodData Central lists ~63 mg per 30 ml espresso, but that figure assumes the classic Italian 7 g basket. Today's specialty standard, inspired by the SCA, typically runs 18-20 g of coffee for a 36-40 ml double ristretto, which pushes real-world caffeine closer to 100-150 mg per cup.

Variety matters a lot. Green Arabica beans hold 1.2 to 1.5 % caffeine by weight, whereas Robusta sits at 2.2 to 2.7 %. A traditional Italian espresso blending 20-40 % Robusta into Arabica therefore carries more caffeine by construction than a light-roasted Arabica single origin. Roast level, by contrast, barely moves the needle: caffeine is thermally stable up to 235 °C — above typical bean-core temperatures — so the caffeine loss between a light and a dark roast is only around 5 %.

Extraction time has a surprising role. A ristretto cut at 20 ml already pulls 70-80 % of the available caffeine, because caffeine is highly soluble and leaves the puck quickly. A lungo stretched to 60 ml recovers almost all of it (95 %) but mostly harvests extra bitterness. In other words, a lungo holds only 15-20 % more caffeine than a ristretto despite doubling the water — counter-intuitive but confirmed in the EFSA's 2015 Scientific Opinion.

To calibrate: a 33 cl can of Coca-Cola has about 32 mg, a 25 cl Red Bull around 80 mg, a 5-minute black tea 40-70 mg, a traditional 200 ml Belgian filter coffee close to 150 mg. A specialty double espresso pulled in Brussels, Ghent or Antwerp lands near a Red Bull — but concentrated in 40 ml rather than diluted in 250. Families should take note: EFSA advises children and adolescents (under 18) not to exceed 3 mg/kg/day, which already equals ~90 mg for a 30 kg child, reachable in a single double espresso.

Caffeine by drink: USDA/EFSA benchmarks

Espresso caffeine variability and what drives it

The popular belief that espresso is stronger than filter coffee — usually meaning higher caffeine — is technically incorrect when comparing equal volumes but conceptually correct when comparing standard servings. A 30 mL espresso shot contains approximately 60–90 mg caffeine. A 250 mL filter coffee cup contains approximately 80–120 mg caffeine. By serving, the filter cup often has slightly more caffeine than the espresso. By concentration (per mL), espresso's 2–3 mg/mL vastly exceeds filter coffee's 0.3–0.5 mg/mL — espresso is approximately 6–7 times more concentrated than filter coffee by caffeine content per volume. The 'stronger' perception reflects concentration, not total dose per serving.

The factors that drive espresso caffeine variability within the 60–90 mg range are less obvious than most home brewers assume. Dose (the amount of dry coffee used) has an obvious direct effect: a 20g dose shot contains roughly 30% more caffeine than a 15g dose shot, all else equal. Extraction yield (EY) matters somewhat: higher EY shots extract a higher percentage of the bean's caffeine, but since caffeine is highly soluble, even low-EY shots extract most of the available caffeine. The largest overlooked variable is grind dose retention: grinders that retain significant amounts of coffee between shots create dose inconsistency that affects caffeine per shot — a grinder retaining 2g per dose that was set for an 18g shot actually delivers 16g, reducing caffeine content by 11%.

Going deeper

Varietal differences in caffeine content affect espresso caffeine meaningfully. A shot from high-caffeine varieties (certain commercial Catuaí lines, some Caturra selections) contains measurably more caffeine than a shot from low-caffeine heirloom Ethiopian varieties at identical dose and extraction parameters. This varietal effect — typically ±20% around the species average — is rarely considered by home brewers but is relevant for people managing their caffeine intake. If you are caffeine-sensitive and find that certain specialty coffees affect you more than others at the same serving size, varietal caffeine differences are a plausible explanation that is worth investigating by comparing beans from different origins systematically.