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THCA to THC Calculator
Wondering how much THC a certain THCA percentage could potentially become?
Enter the THCA percentage from your product label or Certificate of Analysis below. Our calculator uses the standard 0.877 THCA conversion factor to estimate total potential THC after decarboxylation.
Simple formulaUse the 0.877 conversion factor
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The Calculator
Estimated total potential THC
22.23%
Theoretical estimate based on the values entered
THCA × 0.877 + Delta-9 THC = Total Potential THC
The result is a theoretical estimate. Actual cannabinoid conversion may vary depending on heat, time, product composition, and other conditions.
What does this result mean?
A product containing THCA and Delta-9 THC has a theoretical total potential THC content based on the values you entered. This is an estimate of potential cannabinoid content. It does not guarantee how much THC will ultimately remain after smoking, vaping, heating, processing, storage, or another form of use.
How do you convert THCA to THC?
To estimate how much THC can potentially come from THCA, multiply the THCA percentage by 0.877. If the product already contains Delta-9 THC, add that percentage afterward.
For example
THCA × 0.877 = potential THC
Potential THC + Delta-9 = total potential THC
The 0.877 conversion factor accounts for the difference in molecular weight between THCA and THC during decarboxylation.
THCA to THC Conversion Chart
Want a quick answer without using the calculator? This chart shows the theoretical THC potential of several common THCA percentages.
| THCA Percentage | Potential THC From THCA |
|---|---|
| 10% THCA | 8.77% THC |
| 15% THCA | 13.16% THC |
| 20% THCA | 17.54% THC |
| 25% THCA | 21.93% THC |
| 30% THCA | 26.31% THC |
| 35% THCA | 30.70% THC |
| 40% THCA | 35.08% THC |
These figures use the formula:THCA × 0.877
They do not include Delta-9 THC already present in the product. If your Certificate of Analysis lists both values, enter both for a more complete estimate.
Why Is the THCA to THC Conversion Rate 0.877?
THCA and THC are closely related cannabinoids, but they do not have the same molecular weight.
THCA contains an additional carboxyl group. During decarboxylation, THCA loses part of that molecular structure, primarily as carbon dioxide, as it converts toward THC.
The approximate molecular weights are:
Dividing the molecular weight of THC by the molecular weight of THCA gives approximately:
That is where the commonly used THCA to THC conversion factor comes from. In simple terms, the theoretical THC equivalent is about 87.7% of the original THCA amount by weight before existing Delta-9 THC is added.
314.5 ÷ 358.5 = 0.877
= Total Potential THC
THCA Conversion Formula
(THCA × 0.877) + Delta-9 THC= Total Potential THC
Does THCA Convert to THC When Heated?
Yes. Heating THCA can cause it to decarboxylate and convert toward Delta-9 THC. The conversion does not happen at one universal temperature or the same rate in every product—temperature, heating time, and product type all influence the reaction.
Does Smoking THCA Convert It to THC?
Rapid heat causes decarboxylation, but combustion can also cause cannabinoid loss along the way.
Does Vaping THCA Convert It to THC?
Heating in a vaporizer can also cause THCA to decarboxylate toward THC.
Theoretical Potential vs. Actual THC
The 0.877 formula describes theoretical potential, not guaranteed usable THC.
How Does THCA Turn Into THC?
HEAT
Expose over time
DECARBOXYLATION
Carboxyl group is lost
THCA vs. THC:
What's the Difference?
- The acidic precursor naturally found in raw cannabis
- Contains an additional carboxyl group
- Has a higher molecular weight than THC
- Can convert toward THC through decarboxylation
- Can be formed when THCA decarboxylates
- Has a lower molecular weight than THCA
- May already be listed separately on a Certificate of Analysis
- Should be added separately when calculating total potential THC
Put the Calculator to Work
Browse a Grooby COA, find the THCA and Delta-9 THC percentages, then plug them into the calculator.
Old-School Strains. Modern Numbers.
Does All THCA Convert Into THC?
Not necessarily. The 0.877 THCA conversion formula represents the theoretical relationship between the molecular weight of THCA and the THC it can potentially produce. Real-world conversion can be different for several reasons.
HEAT
Different temperatures change how quickly decarboxylation occurs.
TIME
How long THCA remains exposed to heat also influences the reaction.
HEATING METHOD
Smoking, vaping, and other forms of heating do not expose THCA to identical conditions.
Some cannabinoids may be lost, degraded, or otherwise fail to remain available during heating and processing.