How much caffeine is in dark chocolate? About 23 mg in a 1 oz (28 g) piece of 70-85% dark chocolate, based on USDA data, roughly a quarter of an 8 oz cup of brewed coffee. Milk chocolate has much less, about 6 mg per ounce. A whole 3.5 oz bar of dark chocolate, though, comes to about 80 mg, close to a full coffee.
So a square or two after dinner is unlikely to matter for most people, but a big evening portion can. To check your own dessert against your bedtime, use the caffeine calculator.
Free toolCaffeine Cutoff CalculatorHow much caffeine is still in you at bedtime, and your latest cup.How much caffeine is in dark chocolate by cacao percentage?
USDA FoodData Central lists 43 to 86 mg of caffeine per 100 g of dark chocolate, depending on the cacao range, which is about 12 to 24 mg per ounce.
| Chocolate (USDA entry) | Per 100 g | Per 1 oz (28 g) | Per bar |
|---|---|---|---|
| Dark, 45-59% cacao | 43 mg | about 12 mg | about 70 mg (162 g bar) |
| Dark, 60-69% cacao | 86 mg | about 24 mg | about 96 mg (112 g bar) |
| Dark, 70-85% cacao | 80 mg | about 23 mg | about 81 mg (101 g bar) |
| Milk chocolate | 20 mg | about 6 mg | about 9 mg (1.55 oz bar) |
| For comparison: brewed coffee, 8 oz | about 95 mg |
You might expect caffeine to climb steadily with cacao percentage. In the USDA data it doesn't quite: the 60-69% group came out slightly higher than the 70-85% group. Those figures rest on only a few lab samples each (three and two), and caffeine varies with the beans, so treat cacao percentage as a rough guide rather than an exact dial. What holds up is that darker chocolate has roughly 2 to 4 times the caffeine of milk chocolate per ounce.
Bar sizes vary by brand, so check the weight on the wrapper and scale from the per-ounce column.
How much caffeine is in cocoa powder and hot chocolate?
A tablespoon of natural unsweetened cocoa powder has about 12 mg of caffeine, while Dutch-processed cocoa has about 4 mg, and a 6 oz mug of hot cocoa made from a mix has about 4 mg.
| Cocoa (USDA entry) | Per 100 g | Typical serving |
|---|---|---|
| Cocoa powder, unsweetened (natural) | 230 mg | about 12 mg per tablespoon (5.4 g) |
| Cocoa powder, processed with alkali (Dutch) | 78 mg | about 4 mg per tablespoon |
| Hot cocoa from mix, made with water | 2 mg | about 4 mg per 6 fl oz mug |
Baking with natural cocoa can add up. Half a cup of natural cocoa (about 43 g) holds roughly 100 mg of caffeine, so a brownie recipe that uses it spreads about a coffee's worth across the pan. A mug of instant hot cocoa, by contrast, is one of the mildest evening options there is.
Will dark chocolate after dinner keep you up?
A single ounce usually won't push you past this site's 25 mg bedtime line, even eaten close to bed, but two ounces or a whole bar can. This table uses the site's caffeine math: remaining caffeine = dose x 0.5^(hours / 5), with an average 5-hour half-life.
| Dessert | Caffeine | Eaten at | Left at 10 PM | Left at 10:30 PM | Left at 11 PM |
|---|---|---|---|---|---|
| 1 oz dark, 70-85% | about 23 mg | 8 PM | 17 mg | 16 mg | 15 mg |
| 1 oz dark, 70-85% | about 23 mg | 9 PM | 20 mg | 18 mg | 17 mg |
| 2 oz dark, 70-85% | about 45 mg | 8 PM | 34 mg | 32 mg | 30 mg |
| 2 oz dark, 70-85% | about 45 mg | 9 PM | 39 mg | 37 mg | 34 mg |
| Whole 101 g bar, 70-85% | about 81 mg | 8 PM | 61 mg | 57 mg | 53 mg |
| Whole 101 g bar, 70-85% | about 81 mg | 9 PM | 70 mg | 66 mg | 61 mg |
| Milk chocolate bar, 1.55 oz | about 9 mg | 9 PM | 8 mg | 7 mg | 7 mg |
The 25 mg line isn't an official limit, just a sensible target. For scale, 2 oz of dark chocolate at 9 PM leaves more at an 11 PM bedtime (34 mg) than a 12 oz can of Coke at 9 PM (about 26 mg). The Coke and Diet Coke breakdown has the soda side of that comparison.
Two ounces of 70-85% dark chocolate takes about 4 hours 20 minutes to drop below 25 mg, and a whole bar about 8 and a half hours. If you're the kind of person a mid-afternoon coffee keeps awake, an evening bar may do the same.
What about theobromine?
Dark chocolate has far more theobromine than caffeine, about 227 mg per ounce of 70-85% dark versus about 23 mg of caffeine, but theobromine doesn't seem to act like caffeine on alertness.
Theobromine is caffeine's chemical cousin and the main stimulant-like compound in cocoa. USDA lists 802 mg per 100 g in 70-85% dark chocolate, 632 mg in 60-69%, 493 mg in 45-59% and 205 mg in milk chocolate.
The research on what it does is thin. In one small controlled study of 24 healthy women, 700 mg of theobromine (about the amount in 3 oz of 70-85% dark chocolate) did not raise self-reported alertness the way 120 mg of caffeine did. It did lower blood pressure at 1 hour and made people rate themselves slightly less calm at 3 hours. The researchers concluded the two compounds act differently, with caffeine having more of the alertness effect.
That study didn't measure sleep, so it can't tell you whether theobromine affects your night. The safest reading is that caffeine is the part of chocolate to count, and that a very large evening portion is worth avoiding if you're sensitive.
How to enjoy chocolate without losing sleep
- Keep the evening portion to about an ounce. That's a couple of squares from most bars.
- Save big portions and baking-chocolate desserts for earlier in the day.
- Choose milk chocolate or hot cocoa from a mix after about 8 PM if you're sensitive.
- Count it with your drinks. Chocolate adds to whatever coffee, tea or soda you've already had. The caffeine in drinks chart lists the common ones.
- Mind the size of the snack, too. A large, rich dessert late at night can bother some people for reasons that have nothing to do with caffeine. See how long before bed you should eat.