Reading a cannabinoid test report: what mg/g, mg/ml and % mean
An analytical result can only be interpreted when the substance, unit and tested sample are considered together. Cannabinoid product labels and test reports often use different measurements. The examples below explain how to read them. They do not describe a particular Parmorcan® batch and contain no recommendations for use.
For printing: our seven-point checklist helps you systematically check the sample, unit and scope of testing when reading a cannabinoid test report.
First check: which substance and which sample?
Before comparing numbers, read the identification of the tested sample and the individual cannabinoid. CBD, CBDA, CBG and CBN are different entries. A value for one substance cannot simply be transferred to another. For the basics, read our article What is CBD?
Also check whether the report relates to the batch in question and what type of material was tested. A distillate and a finished product are different samples. Without the correct link between them, a numerical comparison with the label cannot be completed reliably.
mg/g: mass of a substance per mass of the sample
The unit mg/g means milligrams of the stated substance per gram of the tested sample. A mass fraction of 1% corresponds to 1 g per 100 g, or 10 mg/g. This is a general calculation example. The quantity being expressed must make the meaning of the percentage sign clear; the SI Brochure also emphasises this. [1]
mg/ml: mass of a substance per volume of the sample
mg/ml means milligrams per millilitre. This volume-based measurement differs from mg/g. Conversion requires the density of the specific sample: a value in mg/g multiplied by density in g/ml gives mg/ml. Without an appropriate density, the two numbers must not be treated as equal. Assuming one density for all oils would not provide a sound basis.
Percentages need a reference quantity
A ‘%’ sign alone does not identify the quantity being compared. If the report states a mass fraction, the measurement relates to masses. Other measurements may refer to volume. A comparison with a product label must use the same quantity. The notation alone does not replace this check.
This is also a practical laboratory issue. The US National Institute of Standards and Technology (NIST) examined cannabinoids in hemp oils in its CannaQAP laboratory comparison. The report calls for correct reporting of results and specifically discusses density in conversions. The tested materials were study materials, not Parmorcan® products. The report is a primary analytical source, not a clinical efficacy study. [2]
A quick comparison checklist
Same substance: for example, compare CBD with CBD.
Appropriate sample: check the batch and material identification.
Same reference quantity: explicitly check whether mass or volume is used.
Limits of the result: do not read a value below the limit of quantification as an exact zero. [2]
For further information about laboratory results and detection limits, see What is CBN? You can then compare the published Parmorcan® test reports with the relevant product and batch information. This article does not provide a new individual assessment of those reports.
A clearly stated concentration answers a question about composition. On its own, it establishes neither a health effect nor the absence of every possible contaminant. When units are unclear, asking about the specific report is more useful than assuming a conversion.
Sources
[1] BIPM: The International System of Units (SI), 9th edition, version 4.01, June 2026; section 5.4.7. Official brochure page · DOI
[2] Abdur-Rahman, M.; Phillips, M. M.; Wilson, W. B. (2021): Cannabis Quality Assurance Program: Exercise 1 Final Report, NISTIR 8385, especially report pages 23 and 54. Official publication · DOI
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