Enter the total weight of your cannabis material (flower, concentrate, etc.).
Enter the percentage of THC in the material. For concentrates, this is often high (e.g., 70-90%).
Grams (g)
Ounces (oz)
Pounds (lb)
Kilograms (kg)
Milligrams (mg)
Kilograms (kg)
Select the unit for your input weight.
Calculation Results
Total Material Weight:—
THC Percentage:—
Unit of Measurement:—
Calculated THC Weight:—
Equivalent Mg of Pure THC:—
Weight in Grams:—
Total Pure THC Weight:—
Formula: THC Weight = Total Material Weight * (THC Percentage / 100)
THC Weight Distribution
Comparison of Total Material Weight vs. Pure THC Weight
Weight Breakdown Table
Component
Weight
Unit
Total Material
—
—
Pure THC
—
—
Other Cannabinoids/Terpenes/Matter
—
—
What is THC Weight Calculation?
Calculating THC weight is a fundamental process for understanding the potency and dosage of cannabis products. It involves determining the actual amount of tetrahydrocannabinol (THC), the primary psychoactive compound in cannabis, present within a given quantity of material. This calculation is crucial for cultivators, processors, consumers, and regulators alike. For cultivators, it helps in assessing yield quality. For processors, it's vital for accurately formulating products like edibles, tinctures, and concentrates. Consumers and patients rely on it to manage their intake and understand the strength of what they are consuming, especially when dosing for therapeutic or recreational purposes. Misconceptions often arise regarding percentages; for example, a 20% THC flower does not mean 20% of its weight is pure THC, but rather that for every 100 units of weight, 20 units are THC. This precise calculation of THC weight ensures consistency and safety in product formulation and consumption. Understanding THC weight is also key when discussing cannabis potency.
Who should use it:
Cannabis cultivators assessing crop quality and yield
Cannabis product manufacturers formulating edibles, concentrates, and topicals
Medical and recreational cannabis consumers managing dosage
Researchers studying cannabis compounds
Regulators and testing laboratories ensuring product compliance
Common misconceptions:
That THC percentage directly equates to a psychoactive "high" without considering the total weight consumed.
Assuming all weight in a cannabis product is either THC or plant matter; a significant portion is water, other cannabinoids, terpenes, and inert plant material.
Confusing weight percentage with volume or concentration in liquids.
THC Weight Formula and Mathematical Explanation
The core formula for calculating THC weight is straightforward and based on percentage:
THC Weight = Total Material Weight × (THC Percentage / 100)
Let's break down the variables and the calculation:
Total Material Weight: This is the absolute mass of the cannabis product you are measuring. It could be a gram of flower, an ounce of concentrate, or a pound of biomass.
THC Percentage: This is the concentration of THC expressed as a percentage of the total material's weight. Laboratories determine this through sophisticated testing.
(THC Percentage / 100): This converts the percentage into a decimal factor (e.g., 20% becomes 0.20).
The multiplication of the total weight by this decimal factor yields the actual weight of pure THC contained within the material. To make calculations more universal and to understand dosage in standardized units, the result is often converted to milligrams (mg), knowing that 1 gram = 1000 milligrams.
Variables Table:
Variable
Meaning
Unit
Typical Range
Total Material Weight
The overall mass of the cannabis sample or product.
0.1% (low-potency hemp) to 99.9% (pure THC isolate)
THC Weight
The calculated mass of pure THC.
Same unit as Total Material Weight, or grams/mg for standardization.
Varies based on inputs.
Practical Examples (Real-World Use Cases)
Example 1: Calculating THC in Flower
A consumer purchases 3.5 grams (half an ounce) of cannabis flower labeled as having 22% THC.
Inputs:
Total Material Weight: 3.5 grams
THC Percentage: 22%
Unit of Measurement: Grams (g)
Calculation:
THC Weight = 3.5 g × (22 / 100) = 3.5 g × 0.22 = 0.77 grams
Intermediate Calculations:
Calculated THC Weight: 0.77 grams
Equivalent Mg of Pure THC: 0.77 g × 1000 mg/g = 770 mg
Weight in Grams: 0.77 grams (already in grams)
Primary Result: Total Pure THC Weight: 770 mg
Interpretation: This means that within the 3.5-gram package of flower, there are approximately 770 milligrams of pure THC. This helps the consumer understand the potency of each serving they might consume. This is a critical number for cannabis dosage.
Example 2: Calculating THC in a Concentrate
A manufacturer is working with a batch of live resin concentrate testing at 75% THC. They have 1 kilogram of this concentrate.
Inputs:
Total Material Weight: 1 kilogram
THC Percentage: 75%
Unit of Measurement: Kilograms (kg)
Calculation:
THC Weight = 1 kg × (75 / 100) = 1 kg × 0.75 = 0.75 kilograms
Intermediate Calculations:
Calculated THC Weight: 0.75 kilograms
Equivalent Mg of Pure THC: 0.75 kg × 1,000,000 mg/kg = 750,000 mg
Weight in Grams: 0.75 kg × 1000 g/kg = 750 grams
Primary Result: Total Pure THC Weight: 750,000 mg
Interpretation: This 1kg batch of live resin contains a substantial amount of pure THC. This information is vital for manufacturing processes, allowing them to accurately calculate how much THC goes into each final product unit and ensure compliance with potency regulations. This calculation is foundational for cannabis manufacturing.
How to Use This THC Weight Calculator
Using the THC Weight Calculator is simple and designed to give you immediate insights into your cannabis material's potency. Follow these steps:
Enter Total Material Weight: Input the total weight of your cannabis product (flower, concentrate, edible, etc.) into the "Total Material Weight" field. Ensure you use a reliable scale for accuracy.
Enter THC Percentage: Input the THC percentage (%) as indicated by lab testing or product information into the "THC Percentage" field. For flower, this is typically between 10-30%. For concentrates, it can range from 50% to over 95%.
Select Unit of Measurement: Choose the correct unit (grams, ounces, pounds, kilograms, milligrams) that corresponds to the "Total Material Weight" you entered. This ensures the calculation is performed with the correct scale.
Click 'Calculate': Press the "Calculate" button. The calculator will instantly process your inputs.
Review Results:
Primary Result (Total Pure THC Weight): This is the most prominent number, showing the total milligrams (mg) of pure THC in your material. This is the key metric for understanding dosage.
Intermediate Values: You'll also see the calculated THC weight in its original unit, the weight in grams, and the total weight in milligrams.
Table and Chart: The table provides a breakdown of the material's composition, and the chart visually compares the total material weight to the pure THC weight.
Interpret the Data: Use the results to inform your consumption decisions (for personal use) or manufacturing processes (for businesses). For example, knowing you have 770mg of THC in 3.5g of flower helps you divide it into appropriate portions for dosing.
Reset or Copy: Use the "Reset" button to clear fields and start over. Use the "Copy Results" button to easily transfer the key figures for documentation or sharing.
Decision-Making Guidance:
For Consumers: Use the 'Total Pure THC Weight' in milligrams to calculate your desired dose. A common starting dose for edibles is often around 5-10 mg of THC.
For Manufacturers: Use the calculated THC weight to precisely formulate products, ensuring consistent potency and compliance with legal limits. The 'Weight in Grams' and 'Mg of Pure THC' are particularly useful.
For Growers: Use the THC percentage data to understand the quality and potential market value of your crop.
Key Factors That Affect THC Weight Results
While the calculation itself is direct, several factors influence the input values and the interpretation of THC weight results:
Accuracy of Lab Testing: The THC percentage is derived from laboratory analysis. Variations in testing methodologies, equipment calibration, and sample representativeness can lead to slight differences in reported percentages. Always rely on reputable, accredited labs for accurate data regarding cannabis testing.
Sample Representativeness: If you only test a small portion of a large batch, the results might not accurately reflect the THC content of the entire batch. Even distribution of cannabinoids is crucial.
Moisture Content: Water has weight but contains no THC. High moisture content can slightly reduce the THC percentage by weight. This is more relevant for fresh flower than for dried and cured products.
Unit Conversion Errors: Mistakes in converting between grams, ounces, pounds, or milligrams can lead to drastically incorrect final calculations. Always double-check your conversions, especially when dealing with large quantities.
Decarboxylation: The THC in raw cannabis exists primarily as THCA (tetrahydrocannabinolic acid), which is non-psychoactive. Heat (through decarboxylation during smoking, vaping, or cooking) converts THCA into active THC. While this calculator uses the reported "THC%" (which often refers to total THC, including converted THCA), understanding this chemical transformation is important for edibles and RSO production.
Other Cannabinoids and Terpenes: While this calculator focuses solely on THC, the total weight also includes other beneficial compounds like CBD, CBG, and terpenes, as well as plant matter, lipids, and waxes. The "Other Cannabinoids/Terpenes/Matter" in the breakdown table represents everything that isn't pure THC. The synergy of these compounds (the "entourage effect") contributes to the overall experience.
Product Type (Flower vs. Concentrate): The starting material significantly impacts the THC percentage. Flower typically has lower THC percentages (10-30%) than concentrates like shatter, wax, or distillate (which can range from 50% to over 95%). This calculator handles both, but the interpretation of results differs greatly.
Frequently Asked Questions (FAQ)
Q: What is the difference between THC percentage and THC weight?
A: THC percentage is a ratio (THC mass / total mass * 100). THC weight is the absolute mass of THC in a given sample, calculated by multiplying the total mass by the THC percentage (as a decimal). For example, 1 gram of flower at 20% THC has 0.2 grams (or 200 mg) of THC weight.
Q: Does this calculator account for THCA?
A: The calculator uses the provided THC percentage. Reputable lab reports often provide "Total THC," which is the sum of THC and the potential THC derived from THCA after decarboxylation. For most practical consumption purposes (smoking, vaping, edibles), this "Total THC" is the relevant figure. If your lab only reports THCA, you would need to convert it first.
Q: How do I convert ounces to grams for the calculator?
A: There are approximately 28.35 grams in one ounce. You can multiply your ounce value by 28.35 to get the equivalent in grams. For example, 1 oz * 28.35 g/oz = 28.35 g.
Q: Is the "Pure THC Weight" the same as a dose?
A: No. The "Pure THC Weight" is the total amount of THC in the material. A dose is the amount you choose to consume at one time. For example, if you have 1000 mg of pure THC, you might choose to take a 10 mg dose, meaning you'd consume 1/100th of the total material (assuming it's homogenous). Understanding cannabis dosage is critical for a safe experience.
Q: Can I use this for CBD products?
A: Yes, the same formula applies. If you have a product with a known CBD percentage, you can use this calculator to find the total CBD weight by inputting the CBD percentage instead of THC.
Q: What if the THC percentage is very low, like 0.3%?
A: This typically indicates a hemp product, which is legally defined as having less than 0.3% THC. The calculator will accurately determine the very small amount of THC present, ensuring compliance with hemp regulations.
Q: How precise do my input values need to be?
A: For accurate results, use the most precise measurements available. Use a calibrated scale for weight and reliable lab data for percentages. Small inaccuracies in input can lead to noticeable differences in the calculated THC weight, especially with large quantities.
Q: What does the "Other Cannabinoids/Terpenes/Matter" weight represent?
A: This represents the remaining weight of the material after accounting for pure THC. It includes water, other cannabinoids (like CBD, CBG), terpenes, flavonoids, plant matter, lipids, waxes, and any other compounds present in the cannabis.
Related Tools and Internal Resources
Cannabis Dosage CalculatorHelps determine appropriate serving sizes based on THC content and desired effect.