The “1g” on a vape cartridge is the net weight of the oil inside. It isn’t the amount of THC, and it isn’t the same as a gram of flower.
What it measures
A 1g cartridge holds about one gram of cannabis oil, often distillate or live resin. That oil includes THC, other cannabinoids, and usually terpenes. If the label says 85% THC, roughly 0.85g of that oil is THC. In volume, a 1g cartridge is often around 1 mL, though oil density varies a little.
What it doesn’t tell you
It doesn’t tell you how long the cartridge will last, since that depends on how often and how deeply you inhale. It also doesn’t compare to flower: a gram of concentrate is far more potent than a gram of flower, so the two aren’t interchangeable.
What to check
Look at the THC percentage and total cannabinoids, the lab results (often a QR code), and whether the packaging is sealed and child-resistant. Some labels list total THC, which counts THCA too. Buy from a licensed shop, where labeling is regulated and every package is tracked. If one won’t scan at checkout, here’s what that means.
Labeling rules vary by state, so the exact format on your package may differ.