THC Calculator

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.

Looking for a specific strain? Search 1,033 strains on licensed NYC dispensary menus, with prices, THC and the shops that carry each one: NYC strains →

THC Flower Calculator

See how many milligrams of THC are in your weed, per gram, joint, and bowl.

How much flower 3.5 g
Custom amountgrams
THC % on the label 20%
5% mild20% average35% very strong
Total THC700mg
200 mg
per gram
100 mg
per joint
50 mg
per bowl
7
joints total
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

Amount15% THC20% THC25% THC
1 gram150 mg200 mg250 mg
Eighth3.5 g525 mg700 mg875 mg
Quarter7 g1,050 mg1,400 mg1,750 mg
Half ounce14 g2,100 mg2,800 mg3,500 mg
Ounce28 g4,200 mg5,600 mg7,000 mg

Most dispensary flower tests between 15% and 25% THC. Use the calculator for an exact number.

Bar chart of milligrams of THC in a joint. A 0.5 gram joint holds 75 mg at 15% THC, 100 mg at 20% and 125 mg at 25%. A 1 gram joint holds 150, 200 and 250 mg. An eighth is 7 joints at 0.5 grams.
THC in a joint at three label strengths, using this page’s grams × THC % × 10 formula.

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.

Bar chart of milligrams of THC in an eighth of flower: 350 mg at 10% THC, 525 at 15%, 700 at 20%, 875 at 25%, 1,050 at 30% and 1,225 at 35%.
Milligrams of THC in an eighth (3.5 g) of flower at each label percentage.

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 NYC weed strains database, which shows the labeled THC for each strain on licensed menus, 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.