How to Read Cannabis Labels in Canada (mg/g to Percent, Explained)

Canadian cannabis labels are genuinely confusing, and it’s not your fault. The number you care about is printed in milligrams per gram instead of the percentage everyone actually uses, there are two different THC values on the same package, and half the label is taken up by a warning in a yellow box. Here’s how to read the thing in under a minute.

The mg/g to percent conversion

In 2019, Health Canada required producers to list THC and CBD in milligrams per gram (mg/g) rather than percentages. The conversion could not be simpler, even though nobody tells you this in the store:

Divide by 10. That’s it. Move the decimal one spot left.

• 194 mg/g = 19.4% THC
• 250 mg/g = 25% THC
• 80 mg/g = 8% CBD

So when a dried flower label reads “Total THC 194 mg/g,” you’re holding what reviews and menus would call a 19.4% strain.

THC vs Total THC (the two-number problem)

Labels show “THC” and “Total THC,” and the gap between them trips everyone up.

Fresh cannabis barely contains THC at all. It contains THCA, a precursor that only converts to THC with heat, which happens when you smoke, vape, or bake it. The breakdown:

• THC is the small number: how much active THC is in the product right now, sitting in the package.
• Total THC is the big number: how much you’ll actually get once heat does its job.

Total THC is the number to shop with. Same logic applies to CBD and Total CBD.

Strain type and terpenes

Labels state whether the product is sativa, indica, or hybrid, and many producers now list the dominant terpenes too. The terpenes are honestly the more useful information, and our terpene guide explains how to use them. Keep in mind that your dose, setting, and own body chemistry shape the experience at least as much as the strain type printed on the box.

Lot numbers, producer info, and the warning label

The rest of the label is traceability. Every package names its federally licensed producer with contact details, and carries a lot number identifying the exact harvest batch your product came from. Cannabis is harvested in cycles and every batch is tested separately, so the lot number is why your label’s potency can differ slightly from the same strain you bought in March. It’s also how a product would be recalled if a batch ever had problems, which is a quiet but real advantage of buying legal.

The health warning is mandatory on every package in Canada. Producers don’t choose whether to include it, only which of the approved warnings you get.

Still squinting at a package?

Bring it in. The budtenders at our High Park store and King West location decode labels all day and would rather you ask than guess, especially on edibles where the dosing math matters most. 19+ only.