How Much Cannabis Should You Buy? A Beginner’s Guide to Quantity and Cost
Cannabis is sold in units that assume you already know what they mean. Nobody buying their first eighth knows whether that is a week's supply or a year's.
This is the translation, plus what things actually cost.
The units
| Unit | Weight | Roughly what it is |
|---|---|---|
| — | — | — |
| Gram | 1 g | 2–4 joints, or several small sessions |
| Eighth ("slice" in Canada) | 3.5 g | The most common US retail size |
| Quarter | 7 g | Four to eight weeks for a light user |
| Half ounce | 14 g | Regular use, or sharing |
| Ounce ("zip") | 28 g | The classic bulk unit; also the common legal possession limit per purchase in many US states |
| Pre-roll | 0.5–1 g | One session |
For a first purchase, one gram is the right size. It is enough for two or three sessions, it costs very little, and it answers the question you actually have — do I like this?
What it costs
Retail prices vary enormously by state, province and product type, so treat any single number as a range rather than a rule:
- Flower: roughly $8–$18 a gram in US recreational markets, less per gram as the package gets bigger. In Canada, legal retail is often CAD $7–$14 a gram.
- Pre-rolls: $5–$15 each.
- Vape cartridges: $25–$60 for a half-gram to one gram.
- Edibles: $15–$30 for a package of ten low-dose pieces in the US; Canadian legal edibles are capped at 10 mg THC per package, which keeps the price lower.
Taxes are added on top and are not trivial — in some jurisdictions they add 20–37% to the shelf price. The price you see on the menu is often not the price you pay.
Bulk is cheaper per gram, but only if you will actually use it. Cannabis degrades, so an ounce bought to save money and smoked over eight months is not the saving it looks like.
How much is "a dose"?
For smoked or vaped flower, a single small pipe bowl holds roughly 0.1–0.3 g, and a first-timer might take two or three puffs of that and stop.
For edibles the arithmetic is different and the stakes are higher, because the effect arrives late. A standard piece in a US package is 5 mg or 10 mg of THC. For someone with no tolerance, 2.5 mg is a reasonable first test; 10 mg is a common "standard" dose for regular users and is too much for many beginners. Canadian legal packages cap the whole pack at 10 mg, which makes them a safer place to start.
The general rule that holds across every product: take less than you think, wait at least an hour before deciding, and remember you cannot undo it.
What regular users actually buy
Someone who uses cannabis a few times a week typically buys an eighth every two to four weeks, or a small vape cartridge that lasts a month. Someone who uses daily might buy an ounce a month. Someone who uses it a few times a year should buy grams, not eighths — the shelf life is not on your side.
If you are unsure where you will land, buy small twice rather than large once. The second purchase is where you learn what you actually like.
Storing what you buy
Flower keeps for months in an airtight, opaque container away from heat and light; it fades noticeably after six months and slowly after that. Edibles and tinctures keep far longer, and vape cartridges last well if kept upright and out of a hot car. Our storage guide has the details.
A simple buying plan
- First visit: 1 g of flower, moderate THC, or a single low-dose edible pack. Under $25 before tax.
- Second visit: buy the size that matches what you actually used the first time, plus one thing you have not tried.
- From then on: buy for flavour and freshness rather than for the best price per gram.
Browse dispensaries near you to compare menus before you go — every listing here links to the business's own site, so you can check current prices and hours rather than trusting a directory snapshot.
General information, not medical advice. Purchase and possession limits vary by jurisdiction and are enforced; check the rules where you are. Cannabis is for adults only.