How much caffeine is in a tablespoon of ground coffee?

in Brewing Coffee, Buying Coffee, Coffee News

Question:

“I’ve been wondering how much caffeine is in a tablespoon of ground coffee (the actual grounds) but I can’t seem to find it on Google. Please help if you can.” – John

Answer:

coffeemoleculeExcellent question, John!

I have a hard time answering coffee questions without geeking out, so this is sure to be longer than what you anticipated as an answer :).

Let’s get the chemistry out of the way.  Caffeine, as well as another alkaloid named trigonelline, account for 1% of the weight of green, unroasted coffee.  As an aside, did you know that the coffee plant produces caffeine as a defense against insects?

Green, unroasted coffee is dense and heavy with moisture, which is expelled from the coffee bean as it’s roasted.  The amount of weight that the coffee bean loses as it’s being roasted varies, but let’s go with 15% of its weight as a good round number.

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This is where the debate starts about whether or not different-roasted coffees contain different amounts of caffeine.  Many years ago, it was my understanding that dark-roasted coffees contained more caffeine.  I wasn’t alone, as I recall many people at the time equating a “strong coffee” with being dark-roasted.  Further on, I started hearing that the roasting process itself burns off trace amounts of caffeine, which would mean that the darker the roast, the LOWER the caffeine.

But wait, there are a couple other ways to look at it!  I’ve been told even more recently that the roaster never reaches a high enough temperature to burn caffeine, therefore caffeine content is THE SAME between a medium-roasted and dark-roasted coffee.  To make matters worse, if the previous statement is true and coffee loses more weight the darker it’s roasted, then we’re back to the understanding that a dark-roasted coffee loses more weight but keeps the same amount of caffeine.  That would mean it indeed has HIGHER caffeine, all other things being equal.

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Sorry for the tangent.  Let’s just assume that 15% of the coffee’s weight in moisture is expelled in the roasting process, and that the caffeine content stays constant.  That would mean that caffeine would go from 1% of the coffee’s composition to about 1.2%.

According to convertunits.com, one tablespoon equals 15 grams.  1.2% of 15 grams is 180 mg.

I invite people to double-check my math, and I am always more than happy to admit when I am wrong.  I checked myself by looking online, and found it universally accepted that one metric cup of coffee contains around 95 mg of caffeine – ironic that number is exactly half of what I came up with above.

17 Comments

  1. The calculation depends on whether the tablespoon is level or a heaing tablespoon, the density of the coffee grounds and the grind size. fyi, I could not get 15 g of medium ground coffee in a tablespoon, even heaped to the max.

    Comment by Anonymous — August 15, 2016 @ 5:16 pm

  2. Thanks for the post!

    The problem with the gram to tbsp conversion is that grams measure weight (or mass if you want to get really technical), while tablespoons measure volume. The conversion stating 15g = 1tbsp is referring specifically to water, and will work for most liquids used in cooking, as they only differ slightly in density from water, but doesn’t work at all for many things. Coffee grounds as mentioned by the previous poster will have different weights for the same volume depending on the density, so you would have to actually weigh your particular tbsp of grounds in order to determine the mg of caffeine.

    If you don’t have a scale that can handle that tiny of a weight, you could instead weigh a larger amount of grounds and divide to get the weight per tbsp, e.g. there are 16tbsp in a cup, so take the weight of a cup of grounds divided by 16, then multiply by the .012 to get the caffeine content.

    Comment by Anonymous — September 29, 2016 @ 10:24 pm

  3. Excellent comment, and you are correct that the measurements apply differently to weight and volume. For those without the appropriate gear to measure exactly, my recommendation is to stick to a consistent scoop/spoon size for measuring coffee, make small adjustments to taste, and then stick to that measurement of coffee for consistency.

    Comment by Marc Wortman — October 3, 2016 @ 10:11 pm

  4. When I got out my kitchen scale, 2 (very slightly rounded) tablespoons of Peet’s drip grind coffee weighed 9g. I measured the amount of coffee using Peet’s 2T measuring scoop.

    Peet’s recommends 2T of coffee per cup (one scoop), so it would work out to about 108mg/cup of coffee.

    Comment by ValerieM — December 9, 2016 @ 9:21 am

  5. can i answer it in very simple how is it ther caffein into it

    Comment by karan — January 1, 2017 @ 3:21 am

  6. You literally missed the most basic point! If the higher the roast the more mositure weight it loses. Than by weight it would have more caffiene but NOT by TBSP. You eill get more light roast coffee in weight per TBSP. Higher the oast the more caffeine in contwxt of weight but wet had more weigjt w the same measurement giving the lower roadt more qeight and caffiene per

    Comment by Josh — April 24, 2017 @ 1:18 pm

  7. OK, we were almost there folks, so close!
    To pick up where Marc left off, yes, coffee is much less dense than water. According to https://www.blackbearcoffee.com/resources/83, there are 5.3 g of ground coffee per Tb. Using Marc’s ratio of caffeine content, this means we take 1.2% of 5.3 grams to obtain 63.6 mg of caffeine per Tb of ground coffee.
    That being said, there is another correction to make. Different varieties of coffee bean contain different ratios of caffeine content (https://www.livestrong.com/article/510061-does-drinking-coffee-all-day-damage-your-kidneys/). 1% is about as low as it gets, and some varieties have up to 2.4% caffeine. (0.024 x 1.2 = 0.029). So, we might expect the Tb of ground coffee to have anywhere between 63.6 and 152.6 mg of caffeine.

    Comment by BoxerBar — May 25, 2017 @ 8:00 am

  8. So here’s what I’m trying to figure out. The coffee maker was given away during the last attempt to give up coffee. I decided to have only 1/2 cup per day. What I’m doing is taking one level tablespoon of dark roast Starbucks ground coffee, bringing it to a boil it in a pan of about 1/3 c water, and letting it steep for five minutes before straining and drinking it. Because all I have is a regular strainer, it’s more like drinking Turkish coffee with some grounds at the bottom. This turns out really well, and it’ll probably end up being the next big Portland coffee fad, but… how much caffeine is this? Any guesses??

    Comment by Anise — June 20, 2017 @ 1:18 pm

  9. Great improvise, Anise. I’d be guessing on the caffeine content, but I believe Starbucks must report the caffeine content of their individual coffees.

    Comment by Marc Wortman — June 21, 2017 @ 1:50 pm

  10. Math sounds about right… I’ll just say a tablespoon isn’t enough to get me through my day! There are brands that produce a higher concentration of caffeine but they’re clearly not as good for you as brewed coffee with all their untapped nutrients.

    Comment by Margaret — October 31, 2017 @ 4:09 pm

  11. What I believe is there is a significant difference in the effect of the caffeine depending on whether or not you grind your own coffee beans or not. The freshness of the coffee plays a vital role in a great cup of coffee and the boost the caffeine gIves the person drinking it. Side note be weary that caffeine withdrawal is in the DSM-V as a Mental Disorder, and has serious side effects which can be life altering and threating.

    Comment by Shamesha — November 24, 2017 @ 6:48 pm

  12. CAN ANYONE TELL ME HOW MANY CALORIES ARE IN 1 TBSP OF WHITE COFFEE GROUNDS, I CANNOT FIND A STRAIGHT ANSWER ANYWHERE HELP!!! THANK U 😊

    Comment by Alicia Rodrigues — November 30, 2017 @ 2:28 pm

  13. 2 Tbsp of coffee for every 6 oz. cup is the proper way to make coffee. Thus, a 12 oz. mug of coffee would have between 127.2 mg and 305.2 mg of caffeine (from the information stated above.

    I’ve read that the average Starbucks grande (16 oz.) has about 200 mg. So, this calculation sounds about right for drip coffee at least.

    I drink Turkish coffee, which is not only ground much more fine, but the grounds remain at the bottom of the cup as I drink. So, I have to assume the caffeine content is a lot higher.

    Comment by Nisan — April 3, 2018 @ 2:31 pm

  14. A tablespoon of coffee would weigh 15 grams if it was more solid (less aerated) I weighed a Tablespoon and it was only 5 grams This is good news for us coffee over doers

    Comment by John — April 15, 2018 @ 9:51 pm

  15. You made a very good start on estimating the caffeine content. However, the reason for the much lower caffeine content sighted in a cup of coffee from your figure is the extraction rate by brewing is in the neighborhood of 50 percent if you go by the caffeine content left in brewed coffee grounds which is approximately 5.8 mg per gram according to https://www.caffeineinformer.com/caffeine-content/coffee-grounds

    This means you would subtract 0.0058 from the caffeine content in the unused coffee grounds of 0.012 resulting in a brewed coffee conversion factor of 0.0062. For me that meant 2 tablespoons of coffee weighing 16 grams times 0.0062 equals 0.0992 grams or 99.2 mg of caffeine in the brewed coffee. Very close to the figure you site in the literature of 95 mg per cup. This explains the discrepancy with you figure of 180 mg.

    Comment by Charles Staubs — August 8, 2018 @ 9:58 am

  16. Now THAT makes sense. And sheds a lot of light on my question.

    Comment by Marc Wortman — August 15, 2018 @ 3:01 pm

  17. over here in Britain they are considering bringing in a ban on caffeine drinks with more than 200mg /litre. I’m afraid your coffee.
    by the way I had 2 cups of coffee this morning, each one with 2 scoops of beans, I have just weighed the same amount now and it comes to a total of 30g coffee at your figure of 1.2% at 50% extraction rate gives me a total of 180 mg or 360mg /litre, almost double the ban limit!
    Argh! I’m doomed

    Comment by owen — August 30, 2018 @ 6:35 pm

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