How Much Caffeine Is in a Cup of Coffee? (Drip Bag, Decaf, Light vs Dark)
A standard 237 ml (8 oz) cup of brewed coffee has about 135 mg of caffeine, according to Health Canada, and a filter drip cup can reach about 179 mg. Decaf has around 3 mg. A single KNDZ drip bag holds 12 g of coffee, which works out to roughly 110 to 150 mg of caffeine in the cup. The biggest thing that changes how much caffeine you get is how much coffee goes into the cup, not the roast or the brewing method.
Caffeine in coffee and other drinks
These figures come from Health Canada's table of caffeine in foods, per 237 ml (8 oz) unless noted.
| Drink | Caffeine |
|---|---|
| Coffee, filter drip | 179 mg |
| Coffee, brewed | 135 mg |
| Coffee, percolated | 118 mg |
| Instant coffee | 76 to 106 mg |
| Black or green tea | 30 to 50 mg |
| Cola (355 ml can) | 36 to 50 mg |
| Instant decaf | 5 mg |
| Decaf coffee | 3 mg |
Treat these as averages. Two cups that look the same can differ a lot, which is what the rest of this guide is about.
How much caffeine is in a drip bag?
Every KNDZ drip bag contains 12 g of ground coffee. Arabica beans are roughly 1.2 to 1.5% caffeine by weight, so a 12 g bag holds about 145 to 180 mg of caffeine before you add water. A pour-over pulls out most of that, but not all of it. That puts a typical cup from one drip bag somewhere around 110 to 150 mg, close to Health Canada's figure for an ordinary cup of brewed coffee.
That is an estimate rather than a lab measurement. Pour more slowly, or let the water sit in the filter longer, and you extract a little more. Pour quickly and you extract a little less. Running more water through the bag pulls out a little more caffeine, but mostly it just makes a bigger, weaker cup.
What changes the caffeine in your cup
| Factor | Effect on caffeine |
|---|---|
| Amount of coffee | The biggest factor by far. Twice the coffee means roughly twice the caffeine. |
| Bean species | Robusta has nearly twice the caffeine of Arabica. |
| Cup size | A 16 oz coffee shop cup can hold double an 8 oz cup. |
| Brewing method | Affects how much of the caffeine is extracted, but less than people think. |
| Roast level | Very small. Light and dark roasts are nearly the same. |
Arabica vs robusta
Robusta beans are around 2.2 to 2.7% caffeine, against 1.2 to 1.5% for Arabica, so a robusta blend can have close to twice the caffeine for the same amount of coffee. Many supermarket blends and instant coffees use some robusta. All KNDZ coffee is 100% Arabica. More in arabica vs robusta.
Does light roast have more caffeine than dark roast?
Barely. Caffeine survives roasting almost untouched, so light, medium and dark roasts all contain about the same amount. The small difference comes down to how you measure. By weight, dark roast has a touch more, because the beans lose more water and you fit more of them in a gram. By the scoop, light roast edges ahead, because the denser beans pack more coffee into the same spoon. Either way, the gap is too small to notice. Our guide to dark roast vs medium roast goes into this in more detail.
A drip bag is measured by weight, so a dark roast bag has, if anything, very slightly more caffeine than a medium roast bag. If dark roast tastes stronger to you, that is flavour, not caffeine.
Brewing method
Method matters less than the amount of coffee. Cold brew, for example, often has more caffeine per cup than iced coffee, but that is because cold brew recipes use far more coffee, not because cold water extracts caffeine better. We go through the research in cold brew vs iced coffee. French press tends to extract a little less caffeine per gram of coffee than filter methods, and espresso packs a lot of caffeine into a very small volume.
How much caffeine is in decaf?
Decaf is not caffeine free, but it is close. Health Canada lists decaf brewed coffee at about 3 mg per 237 ml cup and instant decaf at about 5 mg, compared with around 135 mg for regular brewed coffee. If you are very sensitive to caffeine, a few cups of decaf still add up to a small amount, but for most people decaf is a good way to have coffee in the evening. Our guide to how decaf coffee is made explains how the caffeine is removed.
KNDZ Decaf Medium Roast is 100% Colombian Arabica, available as ground coffee and in drip bags.
How much caffeine is too much?
Health Canada recommends no more than:
- 400 mg a day for healthy adults. The US FDA uses the same figure.
- 300 mg a day for people who are pregnant, breastfeeding or planning to become pregnant.
- 2.5 mg per kg of body weight a day for children and teenagers.
For a healthy adult, 400 mg is about three cups of brewed coffee at Health Canada's 135 mg each, or about three KNDZ drip bags. Remember that tea, cola, energy drinks and chocolate count too. People react to caffeine very differently, so if you have a health condition, take medication or notice it affecting your sleep or heart rate, talk to your doctor about what is right for you.
How to get the same caffeine every time
The easiest way to know what is in your cup is to use the same amount of coffee every time. That is the quiet advantage of a pre-measured drip bag: every KNDZ bag is 12 g, so one bag is one consistent cup. If you brew your own, weigh your coffee rather than using a scoop. Our pour-over coffee ratio guide shows how much to use for each cup size.
Frequently asked questions
How much caffeine is in a cup of coffee?
Health Canada lists about 135 mg for a 237 ml (8 oz) cup of brewed coffee and about 179 mg for filter drip coffee. The real amount depends mostly on how much coffee was used and on the cup size.
How much caffeine is in a drip bag coffee?
A KNDZ drip bag holds 12 g of Arabica coffee, which contains about 145 to 180 mg of caffeine before brewing. A pour-over extracts most of it, so a cup lands at roughly 110 to 150 mg. This is an estimate, not a lab measurement.
How much caffeine is in decaf coffee?
Very little. Health Canada lists decaf brewed coffee at about 3 mg per 237 ml cup and instant decaf at about 5 mg, compared with about 135 mg for regular brewed coffee.
Does light roast have more caffeine than dark roast?
Only very slightly, and it depends on how you measure. Caffeine is barely affected by roasting. By weight, dark roast has a touch more; by the scoop, light roast has a touch more. The difference is too small to notice.
How much caffeine per day is safe?
Health Canada recommends a maximum of 400 mg a day for healthy adults, 300 mg for people who are pregnant, breastfeeding or planning a pregnancy, and 2.5 mg per kg of body weight for children and teenagers. Talk to your doctor if you have a health condition.
Does more water mean more caffeine?
Not much. The caffeine comes from the coffee, so running more water through the same amount of coffee extracts only a little more and mostly gives you a bigger, weaker cup. To get noticeably more caffeine you need more coffee.
Related guides
- Dark roast vs medium roast How roast level changes taste, caffeine and acidity.
- How is decaf coffee made? The four ways caffeine is removed.
- Cold brew vs iced coffee Why cold brew often has more caffeine.
- Low acid coffee What makes coffee taste less acidic.
- Arabica vs robusta Why robusta has nearly twice the caffeine.