Decarb Factor 0.877
A rough multiplier used to estimate THC retention after decarboxylation.
The 0.877 factor is a rule-of-thumb calculator: multiply your starting THCA content by 0.877 to estimate THC after oven decarbing. It's not magic—it's based on the assumption that you'll lose about 12% of your cannabinoids to heat and evaporation under standard home conditions. Real-world loss varies with temperature, time, moisture and oven quirks. It's useful for ballpark math, not precision dosing.
Definition
The 0.877 decarb factor is a multiplier used to estimate the THC content of cannabis after decarboxylation (heating THCA to convert it to THC). The formula is:
Estimated THC % = Starting THCA % × 0.877
For example, if your dried flower tests at 20% THCA, the estimate after standard oven decarbing would be 20 × 0.877 = 17.54% THC.
The 0.877 figure assumes an approximate 12% loss of total cannabinoids during a typical home decarb (oven heating at 220–240 °F for 30–45 minutes). Anecdote
What It Does
The 0.877 factor allows home cooks and consumers to make a quick, rough estimate of how much active THC they will have after decarbing, without sending samples to a lab. It is commonly used in edibles recipes and dosing calculators to predict the final cannabinoid content of butter, oil, or other infusions.
It can help you:
- Estimate the strength of homemade edibles
- Plan approximate dosing before cooking
- Compare expected yield between batches or strains
These are estimates, not guarantees.
What It Doesn't Do
The 0.877 factor is a placeholder, not a law of physics. No data
It does not:
- Predict your exact result (ovens vary; actual loss can be 5–20% or more)
- Account for temperature overshoot or undershoot in your oven
- Adjust for humidity, air circulation, or container type
- Tell you whether decarboxylation actually finished (that is a separate, binary question)
- Apply to non-standard methods (e.g., sous-vide, air fryer, or very long low-heat decarbs)
- Guarantee dosing accuracy for medical or safety-critical use
For precision dosing, lab testing remains the only reliable method. No data
Origins and Accuracy
The 0.877 figure is widely cited in cannabis cooking and harm-reduction communities, but its exact origin in peer-reviewed literature is unclear. Disputed It appears to draw from older cannabis testing data and assumptions about home oven conditions, but no single, definitive source has been widely verified.
Real-world decarb loss varies:
- Well-controlled lab conditions: 5–10% loss Anecdote
- Typical home ovens: 10–20% loss Anecdote
- Poorly monitored or high-heat decarbs: >20% loss Anecdote
If you are dosing for medical purposes or need accuracy, do not rely on the 0.877 multiplier alone. Test your flower before decarbing, and ideally test your finished product or use a calibrated scale and lab-verified potency data.
Using the Factor in Practice
Example calculation:
- Your flower tests at 18% THCA
- You decarb following a standard recipe (oven at 230 °F for 40 minutes)
- Estimated THC after decarb: 18 × 0.877 = 15.79%
- If you infuse 1 ounce (28 g) into butter, estimated total THC in the batch: 15.79 × 28 ÷ 100 = ~4.42 g THC
- Divide by number of servings to estimate per-serving dose
Important caveats:
- This is a rough estimate. Actual result may be ±10–15% different.
- Once decarbed cannabis is mixed into an infusion, potency can vary unevenly across the batch due to settling.
- If making edibles for others, consider starting with a lower estimated dose and increasing gradually.
For harm reduction and safety, err on the side of assuming higher potency, not lower.
See Also
- Decarboxylation Chemistry – the science behind THCA → THC conversion
- Decarb Is Not Binary – why completion matters
- Distillate – a commercial product where THC conversion is much more controlled
Sources
- Reported Weedmaps Education – Dosing homemade edibles and the role of decarb loss estimates.
- Peer-reviewed Hazekamp, A., et al. (2016). 'The medicinal chemistry of cannabis.' Natural Product Reports, 33(8), 1211–1224.
- Book Emery, M. (2016). The Cannabis Sativa Monographs: A Cannabis-Focused Look at Plant Taxonomy, Chemistry, Medicinal Properties, and Cultivation. North Atlantic Books.
How this page was made
Generation history
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