January 25, 2023

How Much THC is in Weed?

THC potency in cannabis can range from near 0% in hemp-derived CBD products to over 90+ percent THC strains of marijuana concentrates. And THC potency is dynamic, with various factors affecting THC levels, from seed to smoke.

It’s often more than reading numbers on a label to figure out THC concentrations. In this guide, we’ll cover:

  • How much THC is in cannabis
  • Types of THC present in recreational cannabis and medical marijuana
  • How to calculate THC content
  • How much THC content determines how high potency cannabis strains are

Read on to learn about THC content in cannabis.

How Much THC is in Weed?

The amount of THC in cannabis varies significantly between different products, strains, and even batches or plants. It even varies over time.

When researchers first accurately measured THC potency in the 1960s, THC content in many strains registered at about 4 to 5%. However, THC content in most strains growers are cultivating is significantly higher today. As more states trend toward legalizing recreational cannabis, more breeders are experimenting with new cannabis strains and working to produce high THC flower.

Often, the strains that are naturally high in THC lean to the sativa dominant side and produce more mental effects. In contrast, indica dominant strains tend to feature both THC and CBD, which offsets those specific THC effects.

According to the Drug Enforcement Administration (DEA), in 2018, the average THC potency of the marijuana seized was around 15%. Today, it’s common to find cannabis flower in legal dispensaries with well over 20% THC, and some higher THC strains with over 30%.

Type of produce further influences the range of THC content. Consumers can choose from classic cannabis flower, as well as marijuana edibles, topicals, tinctures, and concentrates of all different strengths.

Manufacturers extract cannabinoids and terpenes from cannabis flower to make concentrates. After discarding excess organic matter, these concentrated marijuana products contain at least 70% THC, and some deliver over 90% THC.

How is THC Content Calculated?

The THC content is measured in a percentage that indicates its potency. Most legal cannabis states require products to be tested for THC content as well as minor cannabinoids, and to display this information on the label.

The cannabis industry is largely unregulated, so there is substantial variation between cannabis products. Usually, however, the label will list THC, THCA (tetrahydrocannabinolic acid), CBD, CBDA, and sometimes minor cannabinoids such as CBN cannabigerol (CBG) its acidic precursor, CBGA.

The presence of other cannabinoids and terpenes are other key factors in how potent cannabis products are. This synergistic way that these compounds work together is called the entourage effect.

What do these THC percentages mean? You’ll notice that there’s much more THCA than THC in cannabis. Cannabis flower often contains over 20% THCA but just 1 or 2% THC.

THCA, a non-intoxicating precursor cannabinoid, produces THC through decarboxylation, a heating process. In other words, it takes the smoking or vaping process to activate that cannabinoid. This process also occurs naturally over time.

This is why eating plain, unburned cannabis flower is not really capable of causing serious impairment. This is also why subjecting flower to decarboxylation makes it more potent. It is this THC content, the total THC content after decarboxylation that mostly determines THC potency.

Why is total THC value less than THCA value on cannabis products? In part because THC is lighter than THCA. Additionally, the decarboxylation process is not entirely efficient, so some THCA molecules fail to convert to THC and instead degrade into CBN, either during improper storage, dabbing at high temperature, or a similar situation.

THC Content: A Simple Equation for the Most Accurate Number

There is a basic estimate in equation form you can use to calculate THC content. It considers constants such as the weight difference between THC and THCA and the inefficient THC conversion process as well as unique factors such as the amount of THC already present in the cannabis product.

The assumption is that about 75% converts and THC is about 87% of the weight of THCA. This means that the equation looks like this:

(0.75 x 0.877 x %THCA) + %THC = total THC content

For example, a cannabis product with 28% THCA and 2% THC, this is what you would end up with:

(0.75 x 0.877 x %20THCA) + %1 THC = 20.184% total THC content

What Type of THC is in Cannabis?

There is more than one kind of THC; there are multiple chemical analogs, each with its own unique structure that allows it to impart unique effects.

Delta-9 THC. This is the OG of THCs. The psychoactive effects we all know and love from cannabis come from delta-9 THC and the unique double bond structure on the 9th carbon atom of its molecular chain. This allows it to bind with CB1 receptors in the body’s endocannabinoid system (ECS), which are mostly responsible for psychoactive effects. Delta 9’s 5-term side alkyl carbon atom chain also enhances the effects of THC on the body.

Tetrahydrocannabivarin (THCV). After THCA decarboxylation there are actually two compounds produced in relative abundance: THC is the main product and the second most abundant result is tetrahydrocannabivarin or THCV. THCV doesn’t bind as strongly to the body’s CB1 receptors, having a 3-term chain not a 5-term chain as a byproduct of THCA decarboxylation, so at low doses THCV’s psychoactive effects are less pronounced than those of delta 9.

Tetrahydrocannabiorcol (THCC). THCC is a non-psychoactive compound present in cannabis pollen and an analog of THC. In terms of effects, it’s most similar to CBD. THCC is unique for its capacity to bind to the vanilloid receptors (TRPA1), although it doesn’t bind well to either the CB1 or CB2 receptors.

Tetrahydrocannabiphorol (THCP). Discovered in 2019, THCP has two more carbon atoms than delta 9 THC on its alkyl side chain. This longer side chain means stronger psychoactive effects—as many as 33 times more potent.

Delta-7 (THC). Despite having first been synthesized in the 1940s, research into delta 7 THC has been extremely limited. However, we know that delta 7’s double bond is on the seventh carbon atom, and due to this and what we know about other cannabinoids such as delta-8 THC we surmise that delta-7 is significantly less potent than delta 9.

Delta-8 (THC). Another THC analog, delta 8 THC has its double bond on the eighth carbon atom. Delta 8 cannabis consumers report a much milder, more pleasant high from this product which has achieved a loyal following.

Delta-10 (THC). Like delta-8 THC, delta-10 THC is present in trace amounts naturally in cannabis. However, the double bond for delta-10 is located on the tenth carbon atom. As you might guess, delta-10 is even milder in terms of psychoactive effects than delta-8.

Which Factors Affect THC Content?

Many factors affect the THC content of cannabis, such as:

Genetics. The genetics of the cannabis plant is a critical factor influencing THC content.

Each unique genotype even within a strain acts as a blueprint for phenotype and consumer experience, as well as how the live plant responds to conditions in the environment.

Other enzymes and cannabinoids. THC content in a specific strain is heavily determined by the ratio of THC to CBD. This ratio influences classic cannabis side effects; higher levels of THC cause more side effects, whereas higher CBD levels counteract these kinds of side effects. This is why some cannabis strains are highlighted as CBD-dominant or balanced. Depending on which enzymes are in a strain, CBGA will convert into either CBDA or THCA, for example. The latter kind will produce and contain much more THC—so dispensaries are interested in finding growers who can produce those strains.

Environmental factors. Environmental factors also affect THC content, including nutrient availability, quality of soil (if used), the growing method used, the light source and spectrum, temperature, pH and CO2 levels, and humidity. Suboptimal conditions force the cannabis plant to prioritize survival over cannabinoid production.

What’s the Average Dose of THC?

The average dose of THC differs from person to person since everyone has their own tolerance levels. These are based on many factors, including prior cannabis use, age, sex, weight, the individual’s endocannabinoid system, and existing physical and mental health.

In general, though, less than 10 mg of THC is considered a low dose, while a dose between 10 and 30 mg of THC would be strong for beginners and have considerable effects even on experienced users.

Doses above 30 mg of THC are very potent and should only really be consumed by regular cannabis users. One area that causes trouble for new users in particular? Cannabis edibles and high-THC cannabis tinctures invariably result in a stronger high. First-time users beware.

And how much THC is in a joint? This depends not only on what we’re already covered, but also on the amount of THC lost to good old-fashioned combustion.

A one gram, 1000 mg joint of cannabis flower and 25% THC content contains 250 mg of THC. That’s a lot for one at once. However, you probably lose at least half burning away.

Final Thoughts: How Much THC Is In Cannabis?

There are so many factors that impact THC content, and in the end, you’re really just estimating unless you have precise instruments. Everything from the weather to terpenes and other cannabinoids play a role in the amount of THC in a cannabis product.