How to Measure THC Levels in Weed

How to Measure THC Levels in Weed


With cannabis flower, it can be hard for consumers to learn how to measure the quantity of THC or tetrahydrocannabinol on their own instead of only trusting dispensary labels. Knowing how much THC is in the flower will help you determine what type of effects you’ll experience. 

Even more, potency can range from one strain to another, making it difficult to find the dosage that best suits you. 

Not to mention, THC levels have increased in cannabis flower produced commercially, making it even riskier for beginner users. In fact, this interesting throwback claims cannabis is three times as potent as it was in the 1980s.

THC is the main psychoactive component of cannabis. It is responsible for cannabis’ euphoric effects, or buzz. Hence, it’s essential to know its percentage or levels in the weed you consume. So, here’s diving into the subject of how to measure THC in weed to help you with your wellness routines. 

The Science Behind THC Testing

The Science Behind THC Testing

Before we get into how to measure THC, let’s learn the science behind THC testing in today’s  cannabis market. THC testing is widely done in states where cannabis is legal. Cultivators are required to have their flower tested, and to clearly put the percentage on the package that consumers purchase. 

On these labels, you'll often see two different types of THC: THC and THCa. THCa is the acid form of THC and converts into THC upon combustion (or by applying heat, for example, via your lighter or your dry herb vaporizer heating apparatus). 

If both of these THC percentages are printed on the label of the cannabis you purchase, be sure to calculate them together to know the actual THC dosage that will be present upon heating and inhaling. But you can’t do this directly, since THC is 87% of the mass that THCa is, and only 75% is actually converted from THCa to THC. 

Keeping that in mind, here is the equation to use to find out just how much THC will be present in your puffs: 

(0.75 × 0.877 × % THCA) + % THC = Total THC in flower 

Types of Weed You Can Test

With advancements in technology, labs are now able to test almost every type of cannabis product for THC content. Here are the types of weed that can be tested: 

  • Cannabis flower
  • Cannabis edibles
  • Cannabis concentrates
  • Cannabis oil

Testing for THC and CBD in Weed: How it Works

If you don’t have the privilege of taking your weed to a lab for testing or having a legal market that labels it with testing results, there are other methods of learning how to measure THC levels. For instance, there are various at-home kits that can help you check THC and CBD levels. 

Here are the three most popular at-home or DIY tests for THC and CBD in weed. 

  • Color Chart Test Kits (the most cost-effective type)
    At-home color chart test kits come with a container and fluid that you’ll place a small sample of your flower into. After shaking the sample, the solution will turn a color that can be matched to the provided chart to determine the levels of THC.
  • Thin-Layer Chromatography (TLC) Test Kits (comparatively the costlier type)
    TLC test kits not only show levels of THC, but other minor cannabinoids, too. With this test, too, you’ll use a liquid to saturate the flower with. The process separates individual cannabinoids, which are then sprayed with a dye to reveal the percentage of each one.  
  • Testing gadgets (the most expensive type; mainly purchased by cultivators)
    The testing devices can cost over $800 each. They provide an accurate reading of cannabinoid levels. Most gadgets are connected to a smartphone device, where you’ll be provided a chart of cannabinoid percentages after the test is performed as per the instructions. 

Outside of taking your cannabis flower to a testing laboratory, these are the three most popular DIY at-home methods to measure THC.

THC Percentage: How Much is Right for You?

So, once you know how much THC is in the weed you’re going to smoke, how do you know how much is right for you? Keep in mind, cannabis flower usually contains anywhere from 10-30% THC. 

Obviously, the higher the level of THC, the more potent the flower is going to be. Most beginner consumers start in the low THC range of 10-15%. However, if your weed has a higher level of THC, beginners can start off with one small puff, and increase the dosage after they determine how the percentage affects them personally. 

It also helps to find the best temp to vape weed, since different levels of heat will impact the experience. 

Measure THC Levels, But Use a Trusted Vaporizer, Too!

Measure THC Levels, But Use a Trusted Vaporizer, Too!

Last but not least, it’s important to also know that the consumption method used to smoke cannabis also affects potency. The process of THC combustion varies depending on the vaporizer temperature and the type. Be aware that THCA transforming to THC starts at around 180°C.

To fine-tune your vaporizing routines, and ensure you can find the right dosage or potency for you, look no further than the Firefly 2+ weed vaporizer. With Firefly’s handy temperature guide, you can find your ‘sweet spot’ of effects with a smooth, consistent, and reliable device. 

Use only the best vaporizer for your top-shelf cannabis. Learn more about Firefly today.