Terpenes are aromatic compounds responsible for the distinct scent and flavor profiles found across the plant kingdom. These molecules are naturally produced by plants and are highly volatile, meaning they evaporate easily to create a noticeable aroma. In plant-derived products, the concentration and combination of these compounds—such as myrcene, limonene, or linalool—determine the final sensory experience and influence the product’s overall effects through the entourage effect. Consumers seek precise percentage measurements because a higher or more diverse terpene profile is associated with a higher-quality product. Accurate calculation requires specialized laboratory analysis to provide objective, verifiable data.
The Necessity of Laboratory Testing
Obtaining a reliable terpene percentage requires a specialized analytical procedure performed by a third-party laboratory, as simple chemical methods cannot accurately quantify the dozens of individual compounds in a complex sample. The industry standard for this analysis is often Gas Chromatography coupled with a Mass Spectrometer (GC-MS) or a Flame Ionization Detector (FID).
Gas Chromatography works by vaporizing a small sample and injecting it into a coiled column, where an inert gas carries the compounds. The compounds separate based on chemical properties, such as boiling point and polarity. The Mass Spectrometer identifies each separated compound by its unique molecular mass and provides a signal proportional to its concentration. The raw data output is a chromatogram, which shows the concentration of each individual terpene detected in the sample.
Interpreting Raw Data Units
Before calculation, it is important to understand the measurement units provided on a Certificate of Analysis (COA), the document containing the laboratory results. Raw concentration data for individual terpenes is typically reported as milligrams per gram (mg/g) or parts per million (ppm). These units represent a mass-to-mass ratio, indicating the amount of the specific terpene found within the total mass of the sample tested.
Milligrams per gram (mg/g) shows how many milligrams of a compound are present in one gram of the overall product. For example, 5 mg/g of limonene means every gram of the product contains five milligrams of that specific terpene. Parts per million (ppm) expresses concentration as a ratio, indicating the number of mass units of a substance per million mass units of the total mixture.
Step-by-Step Percentage Conversion
The conversion from raw mass-to-mass units to a percentage is straightforward because the metric system simplifies the relationship between the measurements. A percentage represents the amount of a substance per 100 parts of the total product. To convert the most common lab unit, milligrams per gram (mg/g), into a percentage, recognize that one gram equals 1,000 milligrams.
The calculation requires dividing the terpene’s concentration in milligrams per gram by 10 to obtain the percentage by weight. For instance, if the lab report shows a concentration of 10 mg/g for linalool, dividing 10 by 10 yields 1, meaning the product contains 1% linalool by weight. If the raw data is provided in parts per million (ppm), divide the ppm value by 10,000 to arrive at the percentage, as 1% is equal to 10,000 ppm. This process is repeated for every individual terpene listed on the Certificate of Analysis.
Calculating the Total Terpene Content
The final step in interpreting the lab results is calculating the total terpene content, which is the sum of all individual terpene percentages. This aggregated number is often the most visible metric on a product label and is used for consumer comparison. To calculate this total, add the percentage value determined for each individual compound, such as myrcene, pinene, and caryophyllene.
For example, if a product contains 1.2% myrcene, 0.8% pinene, and 0.5% caryophyllene, the total terpene content would be 2.5%. This cumulative figure provides an overall measure of the product’s potency. While the total percentage is a convenient summary, the individual percentages are required to understand the full profile and predict the specific flavor, aroma, and effects a product might deliver.