Cannabis Flower Calculations: To determine how many cannabinoids in mg (e.g., THC, CBD) any cannabis flower sample contains, you must have lab-tested percentiles for each cannabinoid and their respective acid forms. That information is often provided and labeled depending on country or state regulations.
Once you have reliable test results for % cannabinoids and % cannabinoid-acid, do these calculations for each relevant cannabinoid and respective acid forms [e.g., THC, THCA, CBD, CBDA, CBN (note to reader CBN is metabolized from THC and does not occur in its acid form)]. For ease of use, you can also use the CannaKeys widgets here:
The lab test usually specifies a cannabinoid in its acid form in % and its decarboxylated forms. As such, firstly, add % of each cannabinoid to the % of their respective acid forms using this formula:
(0.8 x THCA%) + THC% = Total THC %
For example, if your lab test lists 16% THCA and 4% THC, your calculation looks like this.
(0.8 x 16% THCA) + 4% THC = 16.8% THC
Once you have the total % for each cannabinoid, you can convert each % of each cannabinoid to mg using this formula:
In the trial mentioned above, the average lab results contained 20% THC and ~6% CBD. Plugging in these numbers (using 50mg cannabis flower as an example), we calculate the total for each cannabinoid as follows.
The reader is advised that these mathematical steps only approximate amounts becoming bioavailable. This is because several factors cannot be controlled, measured, or predicted precisely, such as the amount of smoke or vapor lost to the atmosphere, the state of each person’s endocannabinoid tone or signaling capacity, the speed with which a cannabinoid crosses the BBB, specific variable in metabolization, to name but a few.
