How this calculator works
Dosing a homemade batch is four multiplications, and almost everyone gets one of them wrong. This calculator runs all four and shows its work, so you can see which assumption is costing you accuracy.
Step one: how much cannabinoid you actually have
A gram of flower is 1000 milligrams. At 20% THC, that gram holds 200mg. Simple enough — but only if the number on your label means what you think it means.
This is where most calculators quietly go wrong. Cannabis produces THCA, an acidic precursor that is not psychoactive. Heat converts it to THC by driving off a carbon dioxide molecule, and that molecule has mass. THCA weighs 358.47 g/mol; THC weighs 314.46 g/mol. The ratio is 0.877. A gram of pure THCA can only ever yield 0.877 grams of THC, no matter how perfect your technique.
Every certificate of analysis in the industry uses this factor to report Total THC = (THCA × 0.877) + THC. If your label already says Total THC, the conversion is baked in and applying it again would undercount. If your lab sheet lists raw THCA, it has not been applied yet. That is why the basis toggle exists — get it backwards and you are off by about 14% in one direction or the other.
Step two: decarboxylation
Converting THCA to THC needs sustained heat. A well-run oven decarb converts roughly 90% of it. Under-decarb and you leave potency on the table; over-decarb and you start converting THC into CBN, which is sedating rather than intoxicating. The decarb calculator works out the time and temperature.
Decarb efficiency applies whichever figure you entered, and this catches people out. A Total THC label folds in the 0.877 conversion factor, but it is defined as the maximum you could get from a complete decarb. Your oven being imperfect still costs you on top of that. The only exception is material that arrives already decarboxylated, like distillate.
Step three: infusion
Cannabinoids are fat-soluble, so they migrate into butter, oil or alcohol — but never completely. Typical transfer rates:
| Carrier | Typical efficiency | Why |
|---|---|---|
| Coconut oil | 85% | Highest saturated fat content of the common carriers |
| Butter | 80% | Milk fat works well; water-bath method keeps temperature stable |
| Olive oil | 75% | Less saturated fat, better flavour for savoury cooking |
| High-proof alcohol | 90% | Most efficient, but extracts more chlorophyll |
Starting material matters too. Distillate is already decarbed and free of plant matter, so it dissolves into fat almost completely. Trim carries more plant material for cannabinoids to bind to, so it runs slightly lossier than flower.
Step four: divide by servings
Total milligrams divided by the number of pieces. The catch is that this assumes your infusion is evenly distributed. It usually is not. Stir thoroughly, and if you are making gummies or chocolates, be aware that cannabinoids will settle in a mould as it sets.
How much should you actually take?
The honest answer is less than you think, and then wait longer than feels reasonable. Edibles are metabolised into 11-hydroxy-THC, which crosses the blood-brain barrier more readily than inhaled THC. A 10mg edible does not feel like a 10mg equivalent of smoking.
- 1–2.5mg — microdose. Functional, mild body relaxation.
- 2.5–5mg — light. Noticeable but manageable for most people.
- 5–10mg — standard. A solid recreational dose for a regular consumer.
- 10–20mg — strong. Experienced users with real tolerance.
- 20mg+ — heavy. Easy to have an unpleasant time here.
If you are unsure, cut a piece in half. The calculator shows a half-serving figure for exactly this reason.
How accurate is this?
The arithmetic is exact. The inputs are not. Home ovens routinely run 25°F off their dial, infusion efficiency varies with time, temperature and agitation, and lab-reported potency carries its own error bars. Treat the result as a well-informed estimate with perhaps ±20% around it, and let that uncertainty push you toward the lower end of your dose range rather than the higher one.
The one thing this calculator will not do is quietly overstate your potency by skipping the 0.877 conversion. That is a real difference, it is checkable, and it is the reason to use this over a calculator that does not tell you which basis it assumes.