How Much Caffeine Is in Coffee Beans? Per Bean and Per Gram
How Much Caffeine Is in Coffee Beans? Per Bean and Per Gram
Green arabica coffee beans average 15.7 mg of caffeine per gram and robusta beans average 19.9 mg per gram, measured by HPLC-MS on 277 individual beans drawn from 260 samples across 12 countries (Caporaso et al., 2018). A dark chocolate-covered coffee bean holds about 12 mg per piece by USDA data. Plain roasted beans have no published per-bean figure because bean size varies, but the math is simple: multiply the per-gram caffeine by the weight of your bean in grams.
Caffeine in coffee beans at a glance
| Item | Basis | Caffeine | Per gram | Source |
|---|---|---|---|---|
| Green arabica bean | per gram, "as is," mean of single beans | 15.7 mg/g (SD 2.3) | 15.7 mg | Caporaso 2018 |
| Green robusta bean | per gram, "as is," mean of single beans | 19.9 mg/g (SD 4.9) | 19.9 mg | Caporaso 2018 |
| Any green bean, full range measured | per gram, "as is," n=277 beans | 9.2 to 31.9 mg/g | 9.2 to 31.9 mg | Caporaso 2018 |
| Plain roasted bean, one bean | per bean | Not published (depends on bean weight) | See formula below | none |
| Dark chocolate-coated coffee bean | 28 pieces, 40 g | About 336 mg total; about 12 mg per piece | 8.4 mg | USDA FDC 169634 |
| Milk chocolate-coated coffee bean | 1 oz (28.35 g) | About 227 mg; per piece not published | 8.0 mg | USDA FDC 169637 |
| Taza 55% dark espresso beans | 28 g serving | 135 mg | 4.8 mg | Taza product page |
| Brewed coffee (for scale) | 8 fl oz, 237 g | About 95 mg | 0.4 mg | USDA FDC 171890 |
| Espresso (for scale) | 1 fl oz, 29.6 g | About 63 mg | 2.1 mg | USDA FDC 171891 |
Sources: Caporaso et al. 2018 (Food Research International), USDA FoodData Central, Taza product page; checked Oct 31, 2026. Computed columns use the formulas shown below.
How much caffeine is in one coffee bean?
No USDA entry or peer-reviewed study we found publishes a per-bean caffeine figure for a plain roasted coffee bean, because bean size varies too much. The formula is straightforward:
Caffeine per bean = mg per gram × weight of one bean in grams
To get a real number, weigh 10 beans on a kitchen scale, divide the total grams by 10, and multiply by the per-gram figure for your species. Arabica green beans run 15.7 mg/g, robusta 19.9 mg/g; roasted beans concentrate slightly higher per gram (see the roasting section below).
For chocolate-covered beans, the USDA does publish a per-piece figure: one dark chocolate-coated coffee bean comes to about 12 mg of caffeine (335.6 mg ÷ 28 pieces, from USDA FDC 169634).
Arabica vs robusta caffeine
Arabica and robusta are the two species that account for virtually all commercial coffee. In the Caporaso 2018 single-bean study, arabica beans averaged 15.7 ± 2.3 mg/g and robusta averaged 19.9 ± 4.9 mg/g on an "as is" (not oven-dried) basis, with the difference statistically significant at p < 0.001 (Caporaso et al., 2018).
The ranges overlap. The same paper notes overlap "especially around 20 to 25 mg/g" on a dry weight basis, meaning a high-caffeine arabica bean can match a low-caffeine robusta bean. Literature ranges the authors cite: arabica 0.90 to 1.3% and robusta 1.51 to 3.33% on a dry weight basis. Origin, altitude and genetics all push a bean's caffeine up or down within those bands.
If you drink espresso blends (which often mix arabica and robusta), the per-shot caffeine depends on the blend ratio and the dose of ground coffee. See how much caffeine is in a shot of espresso for those numbers.
Does roasting change the caffeine in a bean?
Caffeine itself is thermally stable. Caporaso et al. describe it as "a heat stable methylxanthine" (PMC5886291). The bean loses mass during roasting (water, CO₂, volatile compounds), but the caffeine molecule largely survives.
In a separate single-bean study by the same group, beans lost an average of 15.3% of their weight in a medium roast (Caporaso et al.), which concentrates the remaining caffeine per gram. Using that 15.3% figure:
- Roasted arabica (computed): 15.7 ÷ 0.847 ≈ 18.5 mg/g
- Roasted robusta (computed): 19.9 ÷ 0.847 ≈ 23.5 mg/g
These are computed estimates that assume no caffeine is lost in roasting. The total caffeine in each individual bean stays roughly the same; it is the per-gram figure that ticks up because the bean weighs less.
For how light, medium and dark roasts affect your brewed cup, see how much caffeine is in a cup of coffee.
Chocolate-covered espresso beans: caffeine per serving
Chocolate coating adds weight and dilutes the per-gram caffeine, which is why chocolate-covered beans show lower mg/g than plain green beans despite containing the same bean inside.
USDA dark chocolate-coated coffee beans (FDC 169634): 839 mg caffeine per 100 g. A serving of 28 pieces weighs 40 g and delivers about 336 mg of caffeine, or roughly 12 mg per piece.
USDA milk chocolate-coated coffee beans (FDC 169637): 800 mg per 100 g. The listed serving is 1 oz (28.35 g), which works out to about 227 mg. USDA does not publish a piece count for this entry.
Taza 55% dark chocolate-covered espresso beans (product page): 135 mg per 28 g serving, sold in a 3.5 oz bag for $7.99. Pieces per serving are not published. Its per-gram figure (4.8 mg/g) is lower than USDA's 8.4 mg/g for dark chocolate beans; coating weight changes the per-gram number, so two products can differ even with similar beans inside.
How many coffee beans reach 400 mg?
The FDA cites 400 mg of caffeine a day as the amount not generally associated with negative effects for healthy adults. Here is how quickly different forms of coffee bean get there:
| Form | Unit | Caffeine per unit | Units to reach 400 mg |
|---|---|---|---|
| USDA dark chocolate-coated bean | 1 piece (~1.4 g) | ~12 mg | About 33 pieces |
| Taza 55% dark espresso beans | 28 g serving | 135 mg | About 3 servings (84 g) |
| Plain green arabica bean | 1 gram | 15.7 mg | About 25.5 g of beans |
| Plain green robusta bean | 1 gram | 19.9 mg | About 20.1 g of beans |
Count every other caffeine source in your day: brewed coffee, tea, energy drinks, supplements. The running total is what matters.
The FDA also notes that toxic effects such as seizures can appear with rapid consumption of around 1,200 mg of caffeine (FDA, "Spilling the Beans"). That is roughly 100 dark chocolate-coated beans eaten all at once.
Who should go easy on eating coffee beans
Caffeine from beans adds to every other source in your day. People who should limit intake or talk to a clinician first: those who are pregnant or breastfeeding, those with heart rhythm problems, people managing anxiety disorders, anyone taking stimulant medications, and anyone under 18. If you take medication that interacts with caffeine, ask your prescriber before adding a new source.
Related from Roon
- How much caffeine is in a cup of coffee
- How much caffeine is in a shot of espresso
- How much caffeine is in dark chocolate
- Is 200 mg of caffeine a lot?
Frequently Asked Questions
Is it safe to eat coffee beans?
For healthy adults, eating coffee beans in moderate amounts is fine. The caffeine counts toward the same FDA 400 mg daily figure as brewed coffee or any other source. A handful of 10 USDA dark chocolate-coated beans adds roughly 120 mg, more than an 8 fl oz cup of brewed coffee (about 95 mg).
Do espresso beans have more caffeine than other coffee beans?
"Espresso bean" is a roast and grind designation, not a separate species. The caffeine in a bean is driven by species (arabica vs. robusta) and growing conditions. An "espresso roast" arabica bean has essentially the same total caffeine as a "filter roast" arabica bean of similar size, because caffeine survives roasting largely intact.
How many coffee beans make a cup of coffee?
A standard 8 fl oz brewed cup holds about 95 mg of caffeine (USDA FDC 171890). If you are eating USDA dark chocolate-coated beans at 12 mg each, that is about 8 beans to match one cup. For plain roasted beans, you would need to weigh them: 95 mg ÷ mg-per-gram for your bean = grams needed, then divide by your average bean weight.
Does a decaf coffee bean still have caffeine?
Yes. Decaffeination removes most but not all caffeine. The FDA notes that an 8 fl oz cup of decaf brewed coffee typically contains 2 to 15 mg of caffeine. For a deeper look, see how much caffeine is in decaf coffee.
Caffeine You Can Count, Pouch by Pouch
The trouble with eating coffee beans for caffeine is the math: every bean is a different size, every coating changes the concentration, and you are guessing your dose. Roon is a zero-nicotine oral pouch that delivers exactly 80 mg of caffeine per pouch, about the same as seven USDA dark chocolate-coated espresso beans, with no guesswork.
The formula is built for duration. Methylliberine (Dynamine, 25 mg) slows caffeine clearance: a randomized, double-blind crossover PK study (n=12) found it nearly doubled caffeine's half-life from 7.2 to 15 hours with no higher peak (study). That trial dosed 100 mg methylliberine with 150 mg caffeine, about 4× and 1.9× a Roon pouch, so the mechanism is directionally the same, not a direct measurement of Roon. A 15-hour half-life is not 15 hours of felt energy; a pouch is built for a felt window of roughly 6 to 8 hours, rounded out by 60 mg L-theanine and 5 mg theacrine (TeaCrine). Plan your last pouch at least 8 hours before bed, and stay within Roon's cap of 4 pouches a day.
Pricing runs from $9.16 per tin on the 12-tin subscription, as little as $0.61 per pouch. Fifteen per tin, zero sugar, Cool Mint. Give them a try.
Sources
- Caporaso N, Whitworth MB, Grebby S, Fisk ID. Non-destructive analysis of sucrose, caffeine and trigonelline on single green coffee beans by hyperspectral imaging. Food Res Int. 2018;106:193-203. PubMed | PMC5886291
- USDA FoodData Central: Dark chocolate-coated coffee beans (169634), Milk chocolate-coated coffee beans (169637), Brewed coffee (171890), Espresso (171891)
- Caporaso N, et al. Variability of single bean coffee volatile compounds of Arabica and robusta roasted coffees analysed by SPME-GC-MS. PMC5960070
- Taza Chocolate. Chocolate Covered Espresso Beans. Product page
- FDA. Spilling the Beans: How Much Caffeine is Too Much? Consumer update
Written by Roon Team
