What does THC% mean in cannabis flower?


Weed has come a long way since it’s rise in popularity in the 60’s and 70’s…Not only has cannabis gained in potency over the years, but testing and technology allows the potency to be reported to legal consumers, too. If you’ve purchased medical or recreational flower, you’ve seen THC reported as a specific percentage – but how is this % calculated? We’ll breakdown some marijuana math to show how THC percent is determined, and what it means for your high. 

Technical THC

Looking at your pot packaging, can be confusing for anyone not hip with numbers…or not knowledgeable in the acronyms that are used. Most flower products now report a variety of testing information, including % of THC and % of THCa. So what’s the difference? 

THCa and THC are both present in your cannabis flower…but THCa is only activated or converted to THC when decarboxylated – aka, activated by heat. For example, your lighter sparking a bowl, or your torch heating the dab rig you’ll drop your concentrate into, for a hit. For edibles, this activation occurs by slowly baking buds on low heat prior to making the oil to infuse into your cannabis treat. 

Hence, why you can’t eat your bag of bud, and get high off of what you consumed. 

But to uncomplicate the difference, the ‘total THC’ percentage listed on cannabis products combines both levels – THC and THCa. Most simply, total THC % is how much THC is present in the dry flower by weight once the THCa contained is activated, too. Highlighted by the easiest of equations below – 

THCa% + THC% = Total THC %


Molecules on the scale


But with additional research into marijuana, its’ effects and compounds, you may know – nothing is that easy. And what experts have found, is this straight-forward way of equating ‘total thc’ by adding its’ THCa and THC percentages, doesn’t account for the differences in the two elements.


To more accurately calculate the total THC percentage, you also must incorporate the different weights of the THC and THCa molecules. THC is lighter, since it’s losing the ‘a’ upon heat. In fact, it’s 87.7% of the weight of THCA. And if you know anything about math, this difference has to be calculated into the final ‘total THC’ outcome to account for this variation. 


Many cannabis brands achieve this total THC outcome or answer, by completing the following equation – 


(.877 x THCA%) + THC% = Total THC %


Heat making waves


Similar to weight, there are other outlying factors that also affect what seemed to be a simple equation. Like, the heating temperature or device affecting the conversion of THCa to THC. 


At super high heats, THCa can actually degrade or transform into CBN. The device you use to spark up, or how long it’s heated for will also affect the efficiency of THCa turning into THC. 


Experts now report that 75% is the maximum limit of converting THCa to THC when smoking your cannabis product. In layman’s terms… for every 4 molecules of THCa your marijuana holds, only 3 get activated as THC when heating. 


Obviously, this factor complicates the total THC % – making the number not as concrete as it may seem, unless you incorporate the 25% loss. Like the previous methods we discussed, it does however give the consumer, an idea of what to expect as they light up. Brands incorporating this heat information into their Total THC % use the following equation to do so – 


(.75 x .877 x THCA%) + THC% = Total THC%


As dabbing becomes more popular, the internet search ‘proper temperature for dabbing’ has risen too. In fact, thermometers for rigs are even used by dab connoisseurs or integrated into high-tech dabbing nails or devices. Before you indulge into your precious concentrate, brush up on ideal temperatures so you’re not losing essential compounds for your high. 

extreme cream

Nug numbers


Overall, or what these numbers really mean to you is…the higher the total THC %, the higher you’ll get. While other ratios of CBD, or terpenes, may also affect this statement…that’s a lesson we’ll review in our future articles. Stay tuned for all the 4-1-1 on your NUGS, and check out our products for premier cannabis flower with the numbers to back. 

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