Cannabis Measurements Explained: What an Eighth Means and How Weed Is Commonly Sold
For someone new to cannabis, terms such as “eighth,” “quarter,” and “zip” can be as unfamiliar as the products themselves. These names generally refer to fractions of an ounce, while dispensary labels typically show the quantity in grams as well.
An eighth is one-eighth of an ounce and usually contains 3.5 grams of cannabis flower. It is one of the most common quantities sold to individual consumers. The terminology comes from the U.S. customary system, but cannabis is commonly priced and labeled using a mixture of ounces and metric units.
For reference, the National Institute of Standards and Technology lists one standard ounce as approximately 28.35 grams. In cannabis retail, however, an ounce is commonly treated as 28 grams for practical purposes. That difference comes from rounding rather than a separate measurement system.
Common cannabis quantities
- 1 gram: approximately 0.035 ounces
- An eighth: ⅛ ounce, usually 3.5 grams
- A quarter: ¼ ounce, usually 7 grams
- A half-ounce: ½ ounce, usually 14 grams
- An ounce, or “zip”: commonly 28 grams
- A pound: 16 standard ounces, or approximately 453.6 grams
These figures describe dry weight. Products such as concentrates, vape cartridges, tinctures, and edibles may be sold by weight, volume, serving count, or total THC content instead. For example, a cartridge may contain 0.5 or 1 gram of oil, while an edible package may be identified primarily by milligrams of THC.
Licensed-market labeling rules vary by state. California, for example, requires cannabis packaging to list net weight in both metric and U.S. customary units, while Oregon also requires net weight to be shown in grams and ounces. Checking the package label is the most reliable way to confirm the amount in a particular product.
How much is in an eighth?
An eighth contains about 3.5 grams. The actual number of buds can vary considerably because flower density and size differ from one cultivar to another. A jar containing several small buds may weigh the same as one containing a few large buds.
Prices for an eighth are not fixed. They depend on location, taxes, cultivation method, potency, brand, harvest date, and whether the product is sold through a licensed retailer. Because cannabis prices change substantially between markets and over time, a fixed national price range is unlikely to remain useful. Consumers should compare the price per gram, required taxes, and the product’s laboratory-tested cannabinoid content rather than relying only on the package size.
Understanding larger quantities
A quarter is generally 7 grams, and a half-ounce is generally 14 grams. An ounce is commonly sold as 28 grams, although the exact mass of a standard avoirdupois ounce is 28.35 grams. The term “zip” is informal slang for an ounce and may be used in conversations or menus, but the package’s stated net weight takes precedence.
A pound contains 16 standard ounces and weighs approximately 453.6 grams. If someone multiplies sixteen rounded 28-gram cannabis ounces, the result is 448 grams. That is why informal cannabis discussions may describe a pound as either 448 grams or 453.6 grams: the first uses the customary 28-gram retail shorthand, while the second uses the exact conversion from the standard ounce.
Quantity is not the same as potency
Weight tells you how much material is present; it does not tell you how strong the product will feel. Two eighths can contain different percentages of THC, CBD, and other cannabinoids. For regulated products, the label and accompanying laboratory information are more useful indicators of potency than the quantity alone.
It is also important to distinguish flower weight from THC content. An eighth of flower is 3.5 grams of plant material, not 3.5 grams of THC. The amount of THC depends on the product’s tested concentration and how it is consumed.
Storage and freshness
Buying a larger quantity may reduce the number of shopping trips, but cannabis does not necessarily retain the same chemical profile indefinitely. A four-year storage study found that light, temperature, and exposure conditions affected cannabinoid stability, with substantial THC changes under some storage conditions. The study examined specific samples in controlled conditions, so its results should not be treated as a precise expiration timetable for every retail product.
For best preservation, follow the product’s packaging instructions and keep cannabis in a sealed, child-resistant container away from light, heat, excess moisture, and unauthorized users. When buying regulated products, checking the packaging date can also help you choose fresher stock.
In short, an eighth means approximately 3.5 grams, a quarter is about 7 grams, a half-ounce is about 14 grams, and an ounce is commonly sold as 28 grams. Once those basic terms are familiar, the most important comparisons are the net weight, cannabinoid potency, package date, total price, and the rules that apply in the jurisdiction where the product is sold.
NIST’s conversion table provides the standard ounce-to-gram and pound-to-kilogram conversions. California’s cannabis measurement glossary explains how regulated products are categorized by weight, and Oregon’s official cannabis FAQ provides the standard pound conversion. Research on cannabinoid stability is available through PubMed’s record of the four-year storage study.
