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Edible Calculator

Cannabutter Calculator

THC mg per tablespoon of weed butter, and how much weed you need per cup

How much are you using?

How strong is it?

Most dispensary labels print Total THC, which already accounts for the THCA conversion. If your lab sheet only lists THCA, switch the toggle above — the difference is about 14%.

What are you infusing into?

1 cup = 240ml · 1 stick of butter = 120ml

How many servings?

Results

MildStandardStrongHeavy
Heavy20mg+ per serving · Buckle up, space cadet

Per serving

28.4mg

Total batch

453.6mg

Half serving

14.2mg

Per tsp (5ml)

9.5mg

Per tbsp (15ml)

28.4mg

Per ml

1.89mg

Estimates based on the figures you entered. Real-world potency varies with material quality, oven accuracy and technique. Start low, go slow, and wait two hours before redosing.

Decarb: 90%Infusion: 80%Flower

The butter-to-flower ratio

There is no single correct ratio, because the right answer depends entirely on the potency of what you are starting with and the dose you want to end up at. The traditional one-ounce-per-pound figure comes from an era when flower tested around 8% THC. Apply it to modern 25% material and you get butter roughly three times stronger than intended.

Work backwards from the dose instead:

  1. Decide your target milligrams per serving.
  2. Multiply by the number of servings the batch will produce.
  3. Enter weights above until the total matches.

A useful reference point: one cup of butter is 16 tablespoons. If a recipe calls for a cup and makes 24 cookies, each cookie gets two thirds of a tablespoon.

Making it

  1. Decarb first. 30 minutes at 250°F. See the decarb calculator.
  2. Melt butter with water. Equal parts butter and water. The water buffers the temperature and stops the milk solids scorching.
  3. Add material and hold at a low simmer. 160–190°F for two to three hours. It should never boil.
  4. Strain through cheesecloth. Do not wring it out — squeezing forces chlorophyll through and makes the butter bitter and green.
  5. Chill. The butter sets on top of the water and lifts off cleanly. Discard the water.

Storage and labelling

Cannabutter keeps for about two weeks refrigerated and several months frozen. Freezing in a tablespoon-portioned ice cube tray makes dosing trivial later, because each cube is a known quantity.

Label everything with the date and the milligrams per tablespoon. The print button above produces a batch card with those figures and a QR code that reopens this calculation, which is considerably more reliable than remembering what you did three weeks ago.

Frequently asked questions

How much weed do I need for a cup of butter?

A common ratio is 7 to 14 grams of flower per cup (240ml) of butter. Seven grams of 20% material gives roughly 1120mg of THC in the cup before losses, or about 70mg per tablespoon at 80% infusion efficiency. Adjust the weight until the per-serving figure lands where you want it.

How many mg of THC are in a tablespoon of cannabutter?

Divide the total THC in your batch by the number of tablespoons. One cup is 16 tablespoons, so a batch containing 900mg of THC works out to about 56mg per tablespoon. The calculator shows per-tablespoon and per-teaspoon figures directly.

Why is butter only about 80% efficient?

Cannabinoids are fat-soluble, and butter is roughly 80% milk fat with the rest water and milk solids. Some cannabinoid stays bound to the plant material, and some is lost to straining. Coconut oil runs slightly higher because it has more saturated fat to work with.

Do I need to decarb before making cannabutter?

Yes, if you are starting from raw flower. Simmering in butter does convert some THCA, but incompletely and unpredictably. Decarbing separately first is the only way to get a number you can actually calculate from — see the decarb calculator.

Can I make cannabutter stronger?

Use more material per unit of butter, use higher-potency material, or switch to a more efficient carrier. What you cannot do is exceed the cannabinoid content of what you put in — the calculator caps effective infusion at 100% for that reason.

Other calculators

Edible Dosage CalculatorWork out mg of THC per serving for any infusion.Decarb CalculatorTime and temperature to convert THCA into active THC.