Pick an amount, set the THC % from the label, and see the total milligrams of THC, plus how much is in each gram, joint, and bowl.
THC Flower Calculator
See how many milligrams of THC are in your weed, per gram, joint, and bowl.
Adjust joint and bowl size
These numbers show the THC contained in the flower, not how much your body absorbs; smoking and vaping deliver only part of it. Label THC % can vary from batch to batch. For information only, not medical advice.
How Much THC Is in a Gram, Eighth, and Ounce
| Amount | 15% THC | 20% THC | 25% THC |
|---|---|---|---|
| 1 gram | 150 mg | 200 mg | 250 mg |
| Eighth3.5 g | 525 mg | 700 mg | 875 mg |
| Quarter7 g | 1,050 mg | 1,400 mg | 1,750 mg |
| Half ounce14 g | 2,100 mg | 2,800 mg | 3,500 mg |
| Ounce28 g | 4,200 mg | 5,600 mg | 7,000 mg |
Most dispensary flower tests between 15% and 25% THC. Use the calculator for an exact number.
How the Calculation Works
mg of THC = grams × THC % × 10
Example: an eighth of 20% flower is 3.5 × 20 × 10 = 700 mg of THC.
One gram of flower weighs 1,000 mg, so each percentage point of THC equals 10 mg per gram. A 20% strain holds about 200 mg of THC in every gram.
THC vs. THCA on the Label
Raw flower contains mostly THCA, which turns into THC when heated. If a label lists THCA instead of total THC, switch on the THCA toggle in the calculator. It applies the standard 0.877 conversion, since THCA loses part of its weight as it converts.
Licensed New York products list total THC, which already includes that conversion, so most New York shoppers can leave the toggle off.
Frequently Asked Questions
How many mg of THC are in a joint?
A typical 0.5 g joint of 20% flower contains about 100 mg of THC. A 1 g joint of the same flower contains about 200 mg. Only part of that reaches your bloodstream when smoked.
Does all the THC in a joint get absorbed?
No. A large share is lost to combustion and sidestream smoke, and absorption varies a lot from person to person. The calculator shows the THC contained in the flower, not the dose your body takes in.
How accurate is the THC % on the label?
It is a lab result for one sample of a batch, so the flower in your jar can test a bit higher or lower. Treat the result as a close estimate rather than an exact number.
How do I find the THC % of a strain?
Check the product label first. For a general range, see our guide to the 50 best exotic strains or strain reviews such as Jealousy and Gas Runtz.
For information only, not medical advice. Adult-use cannabis in New York is legal for people 21 and older.