How Much THC Is In a Joint? (Based On Research)

How Much THC Is In a Joint? (Based On Research)

Posted by Christian on 26th Apr 2023

Just how much THC is actually in your joint? This is the question that many stoners – perhaps you included! - are beginning to ask, so they can have more influence over how high they are getting.

The amount of THC in a joint depends on multiple factors. These include how potent the cannabis is (i.e. how much THC there is) and how big the joint is. Furthermore, the impact of the high is also influenced by the amount of CBD, a non-psychoactive cannabinoids that, to some extent, suppresses the intoxicating effects of THC.

In this guide, we’ll give you a rough estimate as to how much THC is in a joint. We’ll also provide you with some simple mathematics tricks so you can work out how much THC is in any joint you may be smoking. And we’ll also teach you how to roll fatter joints, which pack in more marijuana for better highs.

How many grams of THC are in a joint?


Everybody rolls a joint slightly differently, and there’s no set amount for the quantity of marijuana – and therefore THC – in a joint. However, some researchers took it upon themselves a few years ago to work out the average amount of cannabis in an American joint. After collecting and crunching a ton of data, they came up with this figure: 0.32 grams, a smidgen under 1/3 of a gram.

If seems quite low to you, then be assured by the fact that the scientists were surprised as well. Of course, that’s just an average, and if you are rolling fat, pure joints then the cannabis and THC content will inevitably be much higher. But let’s work with the 1/3 of a gram statistic.

Imagine you’ve been to the dispensary, picked up some 12% THC cannabis, and are ready to roll one of those average American joints. Why 12%? That was the approximate THC level estimated by experts back in 2014. Given the array of high-strength pot sold in dispensaries nowadays, that average has perhaps increased in recent years.

This 12% figure means that 12% of the entire weight of the flower is comprised of THC. Therefore, every gram of 12% flower contains 120mg of THC. And since the average joint contains about 1/3 of a gram of cannabis, we estimate that the average joint contains about 40mg of THC, or 0.04 grams of THC.

Check out this table to get a close estimate of how much THC is in your joint, whatever the size, and however much THC you’re using!

Strength/size of joint1/4 gram1/3 gram1/2 gram2/3 gram1 gram
5% THC12.5mg THC16.6mg THC25mg THC33.3mg THC50mg THC
10% THC25mg THC33.3mg THC50mg THC66.6mg THC100mg THC
15% THC37.5mg THC50mg THC75mg THC100mg THC150mg THC
20% THC50mg THC66.6mg THC100mg THC133mg THC200mg THC

Manually calculating volume of THC in a joint

Before proceeding with the manual calculation of the milligrams of THC needed in a joint, you have to be familiar first with the term, bioavailability.

This word refers to the proportionate active effect of medicines, foods, drugs, or any substance that is entering a person’s body. Basically, it is your bodily limit. This is because your body most likely cannot absorb all levels and amounts of a particular compound of a specific substance. Whether you intake vitamin supplements, prescription medications, beverages, or food, it has a set bioavailability as it circulates in the body.

This is the same case with THC. It has a certain bioavailability, not based on how much a joint contains, but the ceiling on how much your body can absorb.

So, how do we calculate the correct measurement of a THC in a joint? You may use the following formula below:

Milligrams of THC = Weight of joint (mg) x THC percentage (potency).

For instance, for a full gram joint of a 20% THC flower, you will receive 200 milligrams of THC. This came from the solution:

1000 mg x 0.20 = 200 mg

Although the computation above shows us the amount of THC in a joint, it does not tell how much THC your body is absorbing. There is no straight computation on the answer to this. Instead, it differs per individual depending on several factors. These are as follows:

  • Joint composition (e.g. CBD to THC ratio)

  • Topography of smoking

  • The amount of wasted THC due to its entrapment or as it wafts off a joint end without being consumed (this is different from the mainstream smoke where all are inhaled and exhaled)

  • Bioavailability

Comparison of THC amount per smoking method

Compared to joints, bongs, and vaporizers, joints are seen to contain the lowest estimated amount of THC inhaled. For a joint with 32 mg THC, a joint is known to have 12 mg of THC for joints, 13 mg for bongs, and 17 mg for vaporizers.

Does bioavailability affect you being high?

It’s not a direct computation to say that your bioavailability affects your high. According to experts, it is your puff technique that affects your bioavailability and eventually translates to being high. In other words, your high status is dose-dependent.

So does that mean that improving the efficiency of your puff technique will increase the possibility of being high? Yes, you can intentionally increase it. In fact, there are various individuals who promote the secret breath method.

What is the secret breath method? It is an inhalation technique that results in an extreme effect where one inhalation will translate to as if you’ve inhaled 5 to 10 times. The manner includes drawing various uniform deliberate breaths while lips are pursed. The way this is executed expands the lungs’ alveoli, enabling the consumer to receive more THC than an average puff.

It may be an effective way to give you the high that you prefer. However, this is not recommended to beginners since their bodies might not handle it. But if you’re a seasoned toker, feel free to apply this and you’ll be at your aimed destination.

How much THC is lost when inhaling smoke?

Without testing, you won’t be able to know how much THC was lost when inhaling smoke. The best way to do so is to draw and test your blood. Once you have the figure, all you have to do is subtract the THC in milligrams found in your blood from the amount of THC you started with.

But why does this difference exist? Why is there a variance between the amount of THC you consume from how much is in your joint? There are various reasons for this and it is as follows:

  • A usual joint primarily contains THC in its non-psychotrophic form of THCA.

  • The amount of temperature and time for decarboxylation will differ depending on the amount of consumer THC in a joint.

  • Whenever it’s smoked, the heat from the ignition will convert the THCA to psychoactive THC through decarboxylation. This is the primary process of eliminating the carboxyl group from an acid.

How to correctly roll a joint to fit in more marijuana

So, you’re ready to learn how to roll better joints? Our first tip is to invest in a high-quality grinder that will grind up your bud as finely as possible. It’s much easier to work with a finely-ground flower than a slightly lumpy flower. We also recommend getting a small rolling table you can work on, to keep your weed-rolling operation tidy and organised!

Start off by breaking your cannabis down into small bits before placing it in the grinder. This will help achieve a smooth, and fine ground, which is exactly what you’re looking for. In the unfortunate event that you don’t have a grinder to hand, you can use scissors – although this really is a substitute method rather than a go-to one.

Next, you’ll need to make a crutch. You can use a cigarette filter although most people opt against this as it can negatively affect the potency of your joint. Just take some thin card – a business card will do the trick – fold it over “accordion” style a couple of times, before rolling it into a cylinder. Some companies that sell rolling papers conveniently include thin strips of card for making crutches. While you can get away without using a crutch, it helps make the joint more stable, and allows you to smoke the joint right down to the bottom, eliminating any wastage.

How to correctly roll a joint to fit in more marijuana

Now things start getting a little more fiddly – it’s time to actually fill your joint with cannabis. We suggest using hemp papers, as these are slightly sturdier than cigarette papers. Joints with these papers also burn more smoothly, and don’t contain any nasty flavors.

Place the crutch at one end of the joint, and fill the rest up with finely-ground flower. Make sure the flower is evenly distributed throughout the joint – this is essential for getting the perfect roll.

Pinch the paper with your fingertips and roll back and forth a few times to ensure the flower is tightly packed down into the joint. A tight packing is crucial, or the joint will burn quickly and unevenly, spoiling your experience. Once everything is perfect, tuck the unglued side of the paper into the roll, and gradually spin the joint through your fingers. Start licking the glued paper on the side where the crutch is, and begin tapering it down, working across the joint. Take your time with this step, as this will determine the quality of your joint.

Once you’ve glued the joint together, take a pencil and pack the weed down further into the joint. You may be able to sprinkle in a little more flower to make your joint bigger. Once you’re satisfied, twist the paper to seal the joint, and stop any flower from escaping!

Top tip: Use a four-piece grinder with a kief collector. Highly-potent kief is great for making your joints stronger, and can be sprinkled into the joint itself, or smeared onto the paper.

And that’s just about it! We hope this post has improved your understanding of cannabis joints!