How Much is an Eighth of Marijuana?
When weighing out cannabis products, both standard and metric systems of measurement are used. The most common metric unit used is grams (we don’t deal in kilos in the weed biz) which is used to measure small amounts of product.
Large quantities of cannabis are measured in pounds (as in Colorado sold 148,238 pounds of marijuana (pdf) in 2014) so breaking it down further using the standard system of measurement makes sense. To do this, we assume that a pound weighs roughly 16 oz and that each of those ounces can further be broken down into eight, easy-to-handle parts (or “eighths” in dealer speak).
Eighths are typically weighed out as 3.5 grams. This assumes that an ounce weighs exactly 28 grams which isn’t exactly accurate (in fact, an ounce actually weighs 28.349523125 grams but rounding is easier to calculate and better for overhead). To make up for this discrepancy, some dispensaries offer “weigh heavy” deals where they weigh eighths out at four grams each, so check local deals before making a purchase to get the most for marijuana for your money.
To figure out how much marijuana that really is, let’s assume that the average joint weighs between half and one gram (which should spread between two to four people comfortably, depending, of course, on the tolerance of the consumers). So, if the average joint weighs .7 grams, an ounce of reefer should net about 40 joints total, or roughly enough to get you through a Phish concert! (J/K, don’t smoke 40 joints at once… Seriously.)