Hiya y’all!
Long time no see!
Figured I’d share my latest overhaul of Decarboxulator here, as a few pals have told me to!
In simplicity, it’s a toolkit for decarboxylation-related calculations. A bunch of calculators and tools to eliminate doing redundant shit by hand, particularly when working with cannabinoid mass balances.
I originally built it years ago for my own personal research and experiments. Over time, I kept running into things I wanted to calculate, questions I wanted to answer, or processes I wanted to keep better track of, so I just kept adding to it.
In my state, analytical lab testing isn’t particularly accessible. I got creative and started figuring out ways to infer certain things from measurable changes in mass, rather than needing access to HPLC or mass spec every time I wanted an answer.
A few friends who work in labs ended up finding some of these tools pretty useful too, which is ultimately why they encouraged me to publish the whole thing.
I’ve been using it for years, but recently decided to completely overhaul the UI, revisit the underlying calculations, and make it installable as a standalone app (PWA).
Some of the calculators and why I made them:
1. THCA Percentage Analyzer (probably my favorite)
This one lets you estimate the original THCA concentration of an extract by measuring how much mass it loses during decarboxylation.
The underlying chemistry is pretty simple, I know I’m preaching to the choir here but it can’t be left unsaid:
THCA → THC + CO2
When THCA decarboxylates, each molecule releases one molecule of CO2.
The molar masses are approx:
THCA: 358.47 g/mol
THC: 314.46 g/mol
CO2: 44.01 g/mol
Meaning, for every gram of pure THCA that undergoes complete decarboxylation, approximately 12.277% of its original mass is released as CO2.
So we use that relationship in reverse.
If we observe 1 gram of mass loss attributable to CO2, we know approximately 8.145 grams of THCA must have decarboxylated to produce it.
So, for example, if you start with 10 grams of THCA isolate and finish with 9 grams after complete decarboxylation and the bubbles stop, the calculator can infer an original THCA concentration of approximately 81.45%.
Pretty neat, lol.
Obviously, there are limitations. Terpene volatility, residual solvents, moisture, other volatile compounds, and incomplete decarboxylation can all introduce error. The calculation assumes the observed mass loss is exclusively CO2, so it’s particularly useful with relatively clean, THCA-dominant concentrates where those assumptions are more reasonable.
It’s not a substitute for analytical testing, and it can’t distinguish between multiple acidic cannabinoids contributing CO2. But for my own experiments, being able to make an approximate determination from gravimetric measurements has been incredibly useful.
2. Decarboxylation Progress Tracker
This one came about because I’ve never particularly liked the idea of determining decarboxylation progress by watching bubbles… who’s with me?!
Tracking decarb by bubbles is dumb as fuck when you can chemically mass-equate the reaction! lol.
Bubbles can tell you gas is being released. They don’t tell you quantitatively how much THCA has converted.
If you know the starting THCA mass, you can calculate the theoretical maximum CO2 loss. From there, periodic mass measurements let you estimate how much of that reaction has occurred relative to the theoretical endpoint.
The tracker lets you record those measurements over time, estimate apparent conversion, follow the mass-loss rate, and visualize the process. I’ve also added empirical curve fitting to help estimate when a run might approach its modeled endpoint, provided there’s enough measurement data.
You can save individual sessions, review previous runs, and export the measurements for further analysis.
Of course, the same assumptions about volatile losses apply here. It’s tracking apparent conversion from CO2-equivalent mass loss, not directly measuring cannabinoid concentrations.
Still, I’d much rather have a series of actual measurements than stare at bubbles and guess.
3. Vessel Pressure Calculator / Heatmap
I originally made this one because I was worried about the possibility of breaking glass jars during decarboxylation.
We’re generating CO2 during the reaction, and if that gas is confined inside a vessel, pressure is going to accumulate. I’ve popped far too many Uline jars to count…
So I wanted to understand just how much.
It uses the ideal gas law alongside the above stoichiometry of THCA decarboxylation to estimate the pressure generated under different conditions.
You can enter the amount of material, THCA concentration, temperature, available headspace, and other assumptions to calculate an approximate pressure.
There’s also an interactive heatmap to explore how changing temperature and headspace volume affects the result.
Ultimately though, it’s a simplified physical model. It doesn’t account for every vapor, phase interaction, or like mechanical property of the glass, and it obviously shouldn’t be interpreted as proof that any particular container is safe to pressurize.
I still wouldn’t recommend heating sealed glass jars that aren’t specifically rated for the pressure and temperature involved.
But understanding the potential magnitude of the pressure seemed a hell of a lot better than blindly guessing.
4. Cartridge Formulation Calculator
This one’s a little different, lol.
I’ve never been particularly enthusiastic about the whole distillate + terps cartridge situation, but it’s an unfortunate reality of the industry that’s probably never going to disappear.
If you can’t beat 'em, join 'em and at least try to engineer the experience into something bearable.
I originally wanted an easier way to calculate cannabinoid and terpene ratios without constantly doing the math by hand.
You can build formulations using THC, THCA, CBD, CBG, CBN, THCV, terpenes, and other ingredients, then calculate how much of each component you need for a desired cartridge count and fill weight.
You can also work backwards from the material you have available.
It accounts for the theoretical mass lost if THCA is decarboxylated before filling, so your starting formulation can be adjusted to reach the intended final mass.
It won’t magically tell you whether a formulation tastes good or whether something will crystallize, but it’s handy for figuring out the actual ratios and material requirements.
5. THCA → THC / THC → THCA Calculator
Probably the simplest tools in the collection, but ones I use constantly.
These simply handle the molecular-weight conversions between THCA and THC.
Useful for yield planning, mass accounting, and avoiding repeatedly multiplying or dividing by 0.87723.
For example, inverse calculator lets you work backwards from a desired THC mass to determine how much THCA you would have needed to start with.
It’s purely mathematical and radical of course. We’re not chemically converting THC back into THCA… Although I did peep that carboxylation thread lol
6. Batch Yield Calculator
Intended for batches rather than isolated cannabinoid masses
Enter a starting material weight and THCA percentage, and it’ll calculate the theoretical THC yield, expected CO2 loss, final batch mass, and resulting THC concentration
This one is useful when planning decarboxylation of extracts rather than isolates.
7. Edible Formulation / Dosage Calculator
I ended up adding this because I occasionally wanted to calculate edible formulations without doing a bunch of separate conversions.
You can combine multiple cannabinoid-containing ingredients, work from material weights or known potency percentages, and calculate the estimated THC content per serving.
It handles existing THC and THCA separately, including the mass lost during decarboxylation.
You can also adjust assumed conversion and recovery percentages independently, or work backwards from a target dosage.
Pretty straightforward, but handy when you’re trying to figure out what a recipe actually needs/yields.
A few other things I should probably note
It’s installable as a PWA on desktop and mobile.
It’s completely free. No accounts, subscriptions, or anything like that.
All the calculations run locally on your device. Calculation history and progress-tracking sessions are stored locally too, rather than being unnecessarily uploaded to a backend. (Feel free to look at the code on my GitHub if you desire!)
You can save previous calculations, share calculator inputs through links, and export your progress-tracking data. The app also supports offline use once the necessary files have been cached.
There’s a fair amount of documentation throughout the tools explaining the equations, assumptions, and limitations for anyone curious about the actual math. (Some of it assisted by AI; inevitably!)
I figure if it’s been useful to me and some pals, there’s probably a plethora of peeps here who could get some use out of it too. 
I’ve been using it for quite a while now and have fixed most of the issues I’ve personally encountered, but if you find something broken or notice something questionable in the calculations, don’t hesitate to reply here!
Cheers!