Walk up to a dispensary counter for the first time and you'll hear a small foreign language: 'You want an eighth or a quarter?' If you don't already know that an eighth means 3.5 grams, it's easy to feel lost. The truth is that cannabis weights are simple once you see them laid out — they're just fractions of an ounce — and learning them takes about two minutes. Here's the plain-English guide so you can shop like you've done it a hundred times.
The base unit: the gram
Everything starts with the gram, the smallest standard amount of flower you'll buy. A gram is enough for a couple of joints or several bowls — a fine way to sample a new strain without committing. From there, larger quantities are sold as fractions of an ounce, which is where the slang comes in.
The conversion chart
| Name | Weight | Roughly equals |
|---|---|---|
| Gram | 1 g | A couple of joints |
| Eighth | 3.5 g | ~7 half-gram joints — the most popular size |
| Quarter | 7 g | Two eighths |
| Half (half-ounce) | 14 g | Four eighths |
| Ounce | 28 g | Eight eighths — the standard large unit |
The key numbers to memorize: an eighth is 3.5g, a quarter is 7g, a half is 14g, and an ounce is 28g. Notice the pattern — each step doubles. Once 'eighth = 3.5 grams' clicks, the rest follows.
Why it's called an 'eighth'
The names come from fractions of an ounce (28 grams). An eighth of an ounce is 3.5g, a quarter-ounce is 7g, and so on. The slang is just shorthand for those fractions, a holdover from decades of cannabis being sold by imperial weight. You'll hear 'an eighth' far more often than '3.5 grams,' but they mean exactly the same thing.
How much should a beginner buy?
For most newcomers, a gram or an eighth is the sweet spot. A gram lets you try a strain with zero commitment; an eighth — the most popular purchase overall — gives you enough to enjoy a strain you like without overbuying. Resist the temptation to buy big early on. Flower is best fresh, and proper storage only slows its decline, so there's little point stockpiling more than you'll use in a reasonable window.
The legal limit in New York
Weights matter legally, too. New York allows adults 21 and older to possess up to 3 ounces of cannabis flower and up to 24 grams of concentrate for personal use. That's a generous limit for personal consumption — well beyond what most people carry — but it's worth knowing. For the full rules on buying and carrying, see our guide to how much cannabis you can legally buy and carry in New York.
Price and value
Here's the practical money tip: buying in larger amounts usually lowers the per-gram price. An eighth typically costs less per gram than a single gram, an ounce less per gram than an eighth, and so on — the bulk discount familiar from any other product. But cheaper per gram only saves money if you actually use it before it dries out. The smart move is to balance the bulk discount against freshness, and to compare prices and deals across licensed dispensaries, since the same weight can vary a lot in price from shop to shop.
A note on other formats
These weights apply to flower. Other formats use their own units: edibles are measured in milligrams (mg) of THC, vape carts in grams of oil (commonly 0.5g or 1g), and concentrates in grams of extract. So an 'eighth' is a flower concept — when you move to other formats, the units change with them.
The bottom line
Cannabis weights are just fractions of an ounce: gram, eighth (3.5g), quarter (7g), half (14g), ounce (28g). Memorize 'eighth equals 3.5 grams' and the rest falls into place. Start small, buy what you'll use fresh, lean on bulk pricing only when it makes sense, and you'll never feel lost at the counter again. Educational only — not legal, medical, or financial advice. For adults 21+.