Cannabutter Dosing Chart: mg per Tbsp and Cookie

Homemade cannabutter has no label with a milligram number on it, but it does have arithmetic: every batch starts from flower weight, a lab percentage, and one chemistry constant. This chart runs those numbers forward to the two questions people actually ask at the counter - how strong is a tablespoon, and how strong is a cookie - so "start low" means a number and not a feeling.

Quick answer: cannabutter dosing chart

The rows assume 18% THCA flower (a common mid-strength lab result) decarbed to completion on the 240°F (115°C) / 40-minute cycle, and the 0.877 acid-to-THC conversion every cannabis label in New York is required to apply. Cup counts are cups of butter in the batch; a cookie count assumes the whole batch goes into that many evenly-stirred portions.

Flower per 1 cup butter	Batch total	1-cup batch	2-cup batch	24 cookies
3.5 g (eighth ounce)	552 mg THC	34.5 mg / tbsp	17.2 mg / tbsp	23.0 mg / cookie
7 g (quarter ounce)	1,104 mg THC	69.0 mg / tbsp	34.5 mg / tbsp	46.0 mg / cookie
14 g (half ounce)	2,208 mg THC	138.0 mg / tbsp	69.0 mg / tbsp	92.0 mg / cookie

Those are ceilings, and the section at the end explains what pulls a real batch below them. The immediate read: even the gentlest row is 3-7x a legal dispensary serving, and the bottom row is a package of dispensary edibles compressed into a single tablespoon.

How to read a row

Take the middle row, because it is the batch the machine-method cannabutter recipe makes: 7 g of 18% flower into 1 cup of butter.

• The flower holds 7 × 18% = 1,260 mg of THCA.
• A completed decarb converts 99.9% of it - the rate constants behind that number are the subject of the decarb temperature chart
  • and the molecule sheds its carboxyl group, so 1,260 × 0.999 × 0.877 ≈ 1,104 mg of THC in the jar.
• One cup of set butter is 16 tablespoons: 69 mg per tablespoon.
• Baked into 24 cookies: 46 mg per cookie, if the dough divides evenly - which it mostly does not, which is what the mixing note at the end is for.

A first-time dose of 2.5-5 mg in that batch is a ninth to a fourteenth of one cookie, or a seventh of a tablespoon. That fraction is the entire safety argument of this chart.

The 0.877 step, in one paragraph

THCA is heavier than THC by exactly one carboxyl group: 358.48 g/mol versus 314.47, and the difference leaves the molecule as CO2 when you heat it. Dividing gives 0.877 - so multiply the milligrams of THCA on any lab report by 0.877 and you have the maximum THC the material can yield. Nothing about that is a kitchen convention: New York's Part 128 labeling guidance defines "total THC" on every state dispensary label as THC + (THCA × 0.877), the same formula Colorado's Rule 212 builds its 10 mg per-serving cap on top of. When you run your own batch through the same math, you are doing dose-prep the way the regulators do labeling. The cannabutter dosage calculator applies it to your grams, percentage, and cookie count instead of the table's.

How to dose a batch you cannot test

• Beginner: 2.5-5 mg. That is New York's public starting guidance for edible newcomers (consumer page) - against the chart above, a fraction of one tablespoon in any row.
• Low: 5-10 mg - one legal retail serving in most states; more than a beginner's portion of a home batch deserves.
• Experienced: 10-25 mg, and even then, one portion at a time.
• Never dose on time: the RTI Press review of cannabis edibles (Barrus et al., 2016) documents oral onset at 30-90 minutes with a peak at 2-4 hours, and a liver metabolite that makes the effect hit harder than smoked THC at the same dose. Nothing that has not arrived in the first hour means "take more."

Why every number on this chart is a ceiling

Three real-world taxes the arithmetic cannot collect:

1. Conversion shortfall. The chart assumes a completed decarb. Household ovens drift 10-25°F around the dial, and the acid is not 100% THCA to begin with - drying and storage already converted part of it. If you ran the cycle at temperature, you are close; if you guessed, the decarb calculator shows how far 20 minutes shorter or 20 degrees cooler reaches.
2. Extraction loss. Infusion pulls cannabinoids into fat; it does not pull all of them. The plant matter you strain out keeps a share of the THC, and squeezing the cheesecloth trades waxes and chlorophyll for a few more milligrams.
3. Uneven distribution. RTI's review documents potency variance even in batch-tested commercial edibles; a home jar has no mixing equipment and no assay at all. Butter sets unevenly - stir the melted batch solid before portioning, and keep one batch constant through a recipe.

The honest summary, same as the commercial market's: tested and homogenized products give you a number you can trust, and home batches give you a number to be conservative against.

Making the assumptions true

The gap between the ceiling and the real batch is mostly decided before the butter ever warms. A countertop unit that holds 240°F in a sealed canister - the ÉCRU Herb Decarboxylator Green 2oz runs preset dry cycles for exactly that stage - turns assumption 1 from a guess into a program. And because dose is decided by the whole workflow, the ÉCRU 2 in 1 Decarboxylator & Infuser 3oz holds the 160-190°F infusion band in the same 20 oz canister, so the decarbed weight the chart assumes and the butter you dose against come from one controlled pair of cycles. The step-by-step batch is the machine-method recipe; the chemistry behind the conversion column is what decarboxylation actually does; and a whole pan run end to end, from batch milligrams to a per-square dose, is the cannabutter brownies recipe.

Safety notes

Label the jar with grams, percentage, and date; store it where children cannot reach it. The FDA's 2022 advisory on THC food products exists because accidental ingestion - especially by children - causes serious adverse events, and a dish of set cannabutter looks exactly like food because it is food. Cannabis is legal in some places and not others; work with material that is legal where you live, and nothing on this page is medical advice.

The short version

Ceiling math: grams × lab% × 10 × 0.877 (≈ × conversion if you ran cool), spread over 16 tablespoons per cup or over your cookie count. A quarter-ounce into one cup lands at 69 mg per tablespoon - dispensary-strength by the spoonful. Dose by weight and fraction, start at a beginner's 2.5-5 mg, wait two hours before revising your opinion, and run the whole chart through your own numbers in the dosage calculator.