An eighth of weed is 3.5 grams. A quarter is 7 grams, a half is 14 grams, and an ounce is 28 grams. The names come from fractions of an ounce, and California dispensaries sell flower in those same sizes, so the gram count tells you exactly how much is in the jar. Below: the full table, what each size looks like, and how much you can buy in a day.
How many grams in an eighth, a quarter, a half and an ounce
| Size | Grams | Fraction of an ounce | Roughly how many joints |
|---|---|---|---|
| Gram | 1 g | 1/28 | 1 to 2 |
| Eighth | 3.5 g | 1/8 | 4 to 7 |
| Quarter | 7 g | 1/4 | 8 to 14 |
| Half | 14 g | 1/2 | 16 to 28 |
| Ounce (a “zip”) | 28 g | 1 | 32 to 56 |
| Quarter pound (a “QP”) | 113 g | 4 | Not sold at adult-use retail |
Joint counts assume half a gram to one gram each. Pre-rolls on the menu are labeled with their exact weight.
What an eighth, a quarter and an ounce look like
- A gram is one bud about the size of a grape, or two small ones.
- An eighth (3.5 g) is three or four buds that sit in the palm of your hand. It comes in a small glass jar or a mylar bag.
- A quarter (7 g) fills a small jar.
- A half (14 g) fills a jar the size of a coffee mug.
- An ounce (28 g) loosely fills a quart-size jar or a large bag. Dense indoor flower takes less room than airy outdoor flower, so size alone is a poor guide; the weight on the label is what counts.
Why 28 grams and not 28.35
A true ounce is 28.35 grams. Cannabis retail rounds it to 28, so an eighth is 3.5 grams rather than 3.54. Every jar is sold by its labeled net weight in grams, and the label is what counts, not the nickname on the shelf.
What sets the price
- Brand and cultivar. Sought-after growers and new cuts cost more.
- How it was grown. Indoor flower generally costs more than greenhouse or sun-grown.
- Size. Per gram, a half is a fraction of an eighth.
- Harvest date. Older batches get discounted; the harvest or packaged date is on the label.
- Deals and tax. Our deals are dated and listed with their terms. California and San Francisco taxes are added at checkout.
How much you can buy in California
A licensed store can sell an adult-use customer up to 28.5 grams of flower (just over an ounce) and up to 8 grams of concentrate per day, and that 8 grams includes the cannabis inside edibles and other products (state retail rule 4 CCR §15409; possession limits are in Health and Safety Code §11362.1). Medical patients with a valid recommendation have higher daily limits. The limit applies per customer per day, across orders.
Reading the weight on the label
- Net weight is the cannabis only, not the jar. It is printed in grams.
- Multi-packs of pre-rolls show the total weight and the per-roll weight (for example, 5 × 0.5 g = 2.5 g).
- Infused flower and pre-rolls count toward the flower limit by their total weight.
- Concentrates are sold in grams too (most carts and dab jars are 0.5 g or 1 g) and count toward the 8-gram concentrate limit.
- THC percentage is potency, not weight. A 3.5 g eighth at 25% THC contains about 875 mg of THC in total.
Common questions
How many grams is a QP?
A QP is a quarter pound: 4 ounces, or about 113 grams. That is above California’s daily adult-use purchase limit; medical patients have a higher limit, so ask the store.
How long does an eighth last?
That depends on how you use it. At half a gram per joint, an eighth is about seven joints. Kept in its sealed jar away from light and heat, flower stays fresh for weeks.
Is an eighth the smallest size?
Most brands also sell single grams and 1-gram or 0.5-gram pre-rolls, which are the smallest way to try a strain before buying an eighth.
What is a zip?
Slang for an ounce, 28 grams. The name comes from the zip-top bag an ounce used to come in.
Browse flower by size on our menu, from Henry’s Original value eighths to Alien Labs, or ask our staff at 3407 Geary Blvd. Order ahead for pickup or delivery in San Francisco. More guides.
Updated October 27, 2026. Written by Weedhub, a licensed cannabis retailer in San Francisco.