Cannabis Weight Conversion: Eighths, Ounces & Pounds

Reviewed August 11, 2026. This page explains weight conversions. It does not determine what amount is lawful to buy or possess in any jurisdiction.

An eighth is 3.5 grams, a quarter is 7 grams, a half ounce is 14 grams, and a retail ounce is commonly treated as 28 grams. A mathematical avoirdupois ounce is approximately 28.35 grams, but cannabis menus generally use the rounded 28-gram convention.

Cannabis measurement chart

How many eighths and ounces are in a pound?

By fraction, one pound contains 16 ounces or 128 one-eighth-ounce portions. A half pound contains 8 ounces or 64 eighth-ounce portions, and a quarter pound contains 4 ounces or 32 eighth-ounce portions.

There is one rounding detail to keep straight. Retail cannabis menus commonly treat an eighth as 3.5 g and an ounce as 28 g, while the exact avoirdupois ounce is about 28.35 g. Multiplying 128 retail 3.5 g portions gives 448 g, not the mathematical 453.6 g pound. For a purchase, the stated net weight on the product page and package controls; do not infer it from rounded menu conventions.

If you are comparing actual one-pound listings, use the THCA pound price guide for unit-price math and the Bulk THCA buyer’s guide for grade, bud-size, photo, and batch-report checks.

How many eighths are in an ounce?

There are eight eighth-ounce portions in one ounce. At 3.5 grams each, 8 × 3.5 equals 28 grams.

How many quarters are in an ounce?

There are four quarter-ounce portions in an ounce. At 7 grams each, 4 × 7 equals 28 grams.

How many grams are in a half ounce?

A half ounce is commonly listed as 14 grams. Two half-ounce packages equal one 28-gram retail ounce.

Why does an ounce sometimes equal 28 grams and sometimes 28.35 grams?

The exact avoirdupois conversion is about 28.3495 grams. Cannabis retailers commonly round an ounce to 28 grams so the familiar fractions divide evenly: 3.5, 7, and 14 grams. Read the actual net-weight statement on the product page and package; do not assume a label uses one convention.

Weight is not potency

Grams and ounces measure mass. They do not tell you cannabinoid percentage, total cannabinoid amount, serving size, or effect. Compare the product’s net weight with its batch report and label. Two products with the same weight can have different cannabinoid profiles.

For a cannabinoid report, review the sample identity, result units, and whether a value is a percentage, milligrams per gram, or total amount. Plain Jane’s COA guide explains these fields.

How to compare prices across weights

Divide the listed price by the number of grams to calculate price per gram. For example, a $35 eighth is $10 per gram because $35 ÷ 3.5 = $10. Include discounts or shipping only when they actually apply to the order.

Bud size and product grade can also affect price. Full-size flower, smalls, trim, and bulk material should not be compared solely by the lowest total price. Use the product description and images to confirm what the listing contains.

Legal limits vary

Weight conversions are universal, but purchase and possession rules are not. A jurisdiction may use different limits for hemp, adult-use cannabis, medical cannabis, concentrates, or public possession. Product visibility on a website does not establish that a quantity is lawful for a particular person or destination. Check current official rules and checkout for the exact order.

Frequently asked questions

Is an eighth always exactly 3.5 grams?

That is the standard retail convention. The package’s stated net weight is the controlling product claim.

Is 7 grams a quarter ounce?

Yes, on cannabis menus a quarter ounce is commonly 7 grams.

Is 28 grams a full ounce?

It is the common retail cannabis convention. A mathematical ounce is about 28.35 grams.

Does more weight mean stronger cannabis?

No. Weight and potency are different measurements. Review the exact product and batch report.