You’re standing at the counter with a gram of live rosin in your hand, and suddenly the math hits you — how many grams in an ounce, and how long is this tiny jar actually supposed to last you?

Let’s start with the number that brought you here: how many grams in an ounce? It’s 28.3495 grams, but in the cannabis world we round to 28 grams flat. That’s the universal standard whether you’re buying flower in Shaw or picking up a gram of badder in Dupont Circle. But here’s the thing — when we’re talking concentrates, you’re almost never buying a full ounce at once. You’re working in grams and half grams, which means understanding the smaller conversions matters even more. A single gram of concentrate at 80% THC packs roughly the same punch as an eighth of top-shelf flower, and that context changes everything about how you budget and dose.

At Green Legacy’s dispensary, we walk patients through these conversions constantly — especially folks who are transitioning from flower to concentrates for the first time. It’s not unusual for someone to come in assuming they’ll go through concentrates at the same rate as flower. They won’t. A gram of wax or shatter can last a moderate user a week or more, which is why weed measurements work differently once you leave the flower world behind. We keep our concentrate menu stocked in gram and half-gram increments specifically because that’s how most DC cannabis patients actually shop. And if you can’t make it to us in person, our DC cannabis delivery brings the same selection right to your door.

I’ll never forget the patient from Adams Morgan who came in last year convinced her dab pen was broken. She’d been loading rice-grain-sized amounts into her rig — easily 0.1 grams per session — and burning through a gram every three days. We sat down, pulled out a milligram scale (yes, we keep one behind the counter), and showed her that a proper dab is closer to 0.025 grams. Her eyes went wide. She literally said, ‘So I’ve been using four times too much?’ Yep. That single conversation saved her money and honestly made her experience way better — lower doses, cleaner effects, less coughing. Dosing math isn’t glamorous, but it’s the difference between a good session and a wasted one.