Cannabis Conversions: Metric and Imperial Explained

weed nug on scale

Let's face it, for many of us, math is a difficult subject. This is especially true if you are mixing measuring methods like cannabis does with grams and ounces. Using two different yardsticks can be confusing, not to mention the fractions involved in most small purchases of weed in the U.S.

And now that Canada has legalized marijuana nationwide, there will doubtlessly be a lot of folks on both sides of the 49th parallel north, trying to figure out how to convert metric to imperial or vice versa. So, whether you are curious what an '1/8th' is, or you just want to know how many grams are in a pound; here is a helpful guide for your cannabis conversions.

Check Your Metrics, Protect Your Neck

In case you are not familiar, the Metric System is a decimal system of measurement that has been nearly universally adopted internationally. Also known as the International System of Units (SI), the metric system is the most common and comprehensive system of weights and measures used today.

The metric system was designed to have properties that make it easy to use and widely applicable, such as a handy multiple of 10, decimal based system with many prefixes to quantify measurements using easier to comprehend calculations.

The metric system also has a fairly bloody history, having first been introduced after the French Revolution, colloquially known as 'the Terror.' It is in this sense that you could say, the metric system put the 'deca' in decapitation.

Ace of Base Unit: The Gram

The gram is a (SI) measurement of mass that originally referred to the weight of a cubic centimeter of water. Now, a gram is more simply defined as one one-thousandth of a kilogram, which is the current base unit of the international metric system.

The simple gram is also the most common unit to calculate small increment of cannabis. Every marijuana dispensary sells flowers and concentrates tabulated in grams. And most pre-rolled joints are going to use a standard .5 gram of bud unless otherwise marked.

Grams are also the obvious measurement for cannabis in Canada, though based on the excitement preceding full legalization, soon enough Canadians will be counting in kilograms.

Kilos and the Cartel Connotation

The term 'kilogram' and 'kilo' are common parlances for most of the world, in the United States the term 'kilo' specifically is associated with images of bundles of hard drugs, like cocaine or heroin, as portrayed in Hollywood movies.

Notably culturally popular television programs such as Miami Vice (1984-1990) and Narcos (2015-2017) have conditioned Americans to associate 'kilo' with cocaine from South America specifically.

For this reason, most Americans will use the full word of kilogram instead of the shortened kilo. But considering that a kilo is over twice the weight of a pound, most Americans will probably stick to using ounces before looking up how many grams are in a pound. But in case you need it, here are some commonly needed kilo conversions:

  • 1 Kilogram = 1000 grams
  • 1 Kilogram = 35.27 ounces
  • 1 Kilo = 2.2 pounds

The Sun Never Sets on the (H)Empire

Famous for originating as the length of a monarch's appendage, the Imperial System first came into official use in England and later the whole British Empire. Today, most nations of the former empire have officially adopted the metric system as their main system of measurement; only former colony, the United States continues to use the imperial system in regular commerce.

Officially known as (USCU) United States Customary Units; ounces, pounds, tons, and even grains are all units of dry weight measure that were adopted from the British before George Washington led the hemp-clad continental army. But even though the names are the same, pound for pound and ounce for ounce, these are not the measuring units of King George III.

Ounces; a Fractional Dynasty

Over the years there have been many names for the sandwich baggie full of weed that became a standard ounce; Flip, Zip, and Z being common ones. Today ounces are the most common unit of measurement for cannabis in the United States.

And because cannabis flowers weigh so little and there is not a smaller USCU unit to measure with, most American marijuana consumers are familiar with using fractions when they purchase their stash.

Here is the equivalent weight in grams for fractional ounce purchases:

  • 1 Ounce = 28.35 grams
  • 1/2 Ounce = 14.17 grams
  • 1/4 Ounce = 7.09 grams
  • 1/8 Ounce = 3.54 grams


Typically, the only people in the cannabis industry who are using pounds as a measurement are dispensaries, dealers, and marijuana growers (most likely outdoor). Because of this, a pound of weed is usually considered more than personal consumption in the eyes of the law. But considering that one pound of weed tips the scales at sixteen ounces, one can understand that point of view.

So, if you are a big-league cannabis grower, curious how many grams are in a pound, or even if you were just born between September 23rd and October 23rd, here are the best conversion stats for pounds:

  • 1 Pound = 459.59 grams
  • 1/2 Pound = 226.80 grams
  • 1/4 Pound = 113.40 grams
  • 1 Pound = 16 ounces
  • 1/4 Pound = 4 ounces

Weight for It

There you have it, now you know enough about cannabis weights and measures to deliver an expertly placed order to your local bud-tender, no matter where in North America you are. And knowledge like that is worth its weight in Acapulco Gold.