How much is an eighth? An eighth is one-eighth of an ounce of cannabis, sold as 3.5 grams. It's small enough to try something new and big enough for several sessions, which is why it turns up on so many flower menus. Here's what an eighth of weed in grams really means, what it looks like, how many joints it rolls, what moves its price and how it fits within Michigan's limits.
How much is an eighth? 3.5 grams
Cannabis is weighed in grams but sold in old fractions of an ounce. An ounce is about 28.35 grams, menus round it to 28, and one-eighth of that is 3.5. The exact eighth is about 3.54 grams, a gap of a few hundredths of a gram. So when a menu lists 3.5 grams of weed, it's an eighth.
What an eighth looks like
Picture a few medium buds, or one large bud and some smaller ones, sitting loosely in a small jar. Bud density changes the picture a lot: a tight, heavy eighth can look much smaller than a fluffy one. Licensed packages list their net weight, so the label settles any doubt.
Slang for an eighth
- An eighth or an 8th
- A three-and-a-half or a 3.5, for the grams
- An eighth-ounce, the long form
How many joints in an eighth?
It depends on how much flower goes into each joint.
| Joint size | Flower per joint | Joints from an eighth |
|---|---|---|
| Slim | 0.3 g | About 11 |
| Standard | 0.5 g | 7 |
| Large | 1 g | 3, with a little left over |
Researchers who analyzed more than 10,000 U.S. cannabis purchases estimated the average joint at about 0.31 to 0.32 grams. At that size, an eighth rolls about 11.
Eighth vs. gram: value per gram
An eighth usually costs more per gram than a quarter or a half, but less than buying single grams. To compare, divide the eighth's price by 3.5 and set it next to a gram's price. Bigger isn't automatically better: an eighth you enjoy beats a half you don't. Our cannabis measurements chart shows every size side by side.
What moves the price
The eighth price you see depends on several things:
- Quality tier. Premium, carefully trimmed buds cost more than smalls or shake.
- Potency and strain. High-THC flower and in-demand strains usually cost more.
- Taxes. Adult-use purchases carry a 10% excise tax plus the 6% sales tax, which is figured on the price including the excise, for about 16.6% in total. Registered medical patients pay only the 6% sales tax.
- Wholesale tax. As of October 2026, a 24% wholesale tax has applied since January 1, 2026, when growers and processors first sell adult-use cannabis to retailers. It doesn't appear on your receipt, but it can be passed along.
- Deals and rewards. Promotions change, and our free loyalty program, The Society, adds points to qualifying purchases.
Current prices are on your store's menu.
Why the eighth became a standard jar size
The eighth is the smallest of the common ounce fractions, so it's a low-commitment way to buy a strain by weight. That makes it practical in a few ways:
- Easy to try. You can sample a strain's aroma and flavor without stocking up.
- Easy to finish fresh. A small amount gets used before it dries out.
- Easy to compare. Two different eighths let you judge, side by side, how each one smells and feels to you.
What an eighth is good for
An eighth covers a lot of ground for an occasional consumer: a handful of joints, several bowls or a few weekends of sessions. It's also the natural way to explore. If you're learning what you like, our guide to cannabis flower explains how to read strain types, potency and aroma, and an eighth gives you a low-stakes way to put that into practice.
Michigan possession limits
Michigan's limits leave plenty of room for an eighth:
- Carrying. Adults 21 and older may carry up to 2.5 ounces, which is 20 eighths, with a 15-gram cap on concentrate.
- Buying. Licensed adult-use stores can sell up to 2.5 ounces per transaction and check government-issued photo ID before every sale.
- At home. The home limit is 10 ounces plus your own plants' harvest, and anything over 2.5 ounces has to be kept locked.
- In the car. Using cannabis while driving is off-limits, and so is smoking in a vehicle's passenger area on a public road. Keeping your purchase sealed and out of reach, such as in the trunk, is the cautious habit.
- Across borders. Don't travel across state lines with cannabis.
For the full rundown, see our guide to Michigan cannabis laws. 21+ only. Please consume responsibly.
