An 8th Is How Many Grams? Cannabis Weights, Sizes, Pricing & What to Expect

Most people who've ever bought cannabis have heard the word "eighth" thrown around — but if you've never seen it written out, the maths behind it can feel strangely mysterious. Here's the thing: an eighth is simply 3.5 grams, derived from dividing a 28-gram ounce by eight. That one number unlocks every other common cannabis measurement you'll ever encounter.

Understanding cannabis weights isn't just useful for buyers — it's essential knowledge for home growers tracking yield, planning harvests, and knowing whether their plants are performing to spec. This guide breaks down every common weight, what to expect from each, how Australian pricing stacks up, and why grams matter far more than you might think when you're growing your own.

What Is an Eighth of Cannabis?

An eighth refers to one-eighth of an ounce — the base imperial unit that cannabis has been traded in for decades, even in countries like Australia that otherwise use metric measurements. One ounce equals 28 grams (technically 28.3495 g, rounded to 28 g by convention). Divide that by eight and you get 3.5 grams.

The eighth became the cannabis industry's default unit because it's a practical, affordable quantity. It's enough for multiple sessions without being a large financial commitment, and it fits neatly into a small glass jar or zip-lock bag. For the home grower, 3.5 g is also a useful benchmark — it's roughly what a single, modest autoflower bud site might yield after a dry and cure.

In Australia, cannabis remains regulated under state and territory legislation. Growing for personal or recreational use is still illegal in most states, with the ACT being the notable exception (where adults can legally grow two plants). Medicinal cannabis is regulated federally by the Therapeutic Goods Administration (TGA). All growing references on this page are framed as educational and horticultural — always check your local laws before proceeding.

What Does the Full Cannabis Weight Chart Look Like?

Once you know an eighth is 3.5 g, every other common cannabis unit is simple multiplication. Below is the complete weight chart growers and buyers use worldwide — with the imperial fraction, the gram equivalent, and a practical context note for each.

What Does Cannabis Cost in Australia by Weight?

Australian cannabis pricing is among the highest in the world due to the nation's geographic isolation and regulatory environment. Based on publicly aggregated data from harm-reduction resources and community reporting, here's what Australians typically encounter across common weight units. Note: these figures reflect reported street/grey-market pricing in jurisdictions where personal use occurs — we do not endorse illegal purchase or sale.

Growing your own legal herb in jurisdictions where cultivation is permitted offers dramatic savings. A single autoflower seed costing AU$10–20 can produce 30–80 g of dry flower — the equivalent of AU$450–1,600 worth of product at street pricing. This is why home cultivation (where legally allowed) is so economically compelling.

How Many Joints Can You Roll From Each Weight?

The number of joints per weight depends heavily on rolling style — slim pinners use around 0.4–0.5 g, standard joints use 0.75–1 g, and fat cones use 1.5–2 g. Here's a practical breakdown using three common joint sizes:

Keep in mind that stem removal and shake reduce usable weight by roughly 5–10%. A 3.5 g eighth of well-trimmed, dense flower behaves differently to 3.5 g of loose, dried outdoor material. Density matters for both rolling and for how accurately a small scale reads the weight.

What Grams-Per-Plant Should Home Growers Expect?

For home growers in jurisdictions where cultivation is legally permitted, understanding realistic dry yield in grams is far more useful than trusting breeder marketing claims. Looking at grower-reported harvest data published in public forums and grow journals, a consistent pattern emerges: actual yields run 20–40% below breeder-stated maximums for beginners, and meet or exceed them for experienced growers with dialled-in environments.

Below is a realistic grower-facing yield reference across common grow categories:

• Beginner autoflower, small pot (7–11 L), basic LED: 15–40 g per plant
• Intermediate autoflower, 15–19 L fabric pot, decent LED (≥600 PPFD): 40–80 g per plant
• Experienced autoflower, optimised 600 PPFD+, LST applied: 80–130 g per plant
• Beginner photoperiod feminised, outdoor, first season: 50–120 g per plant
• Experienced photoperiod feminised, outdoor full season: 150–400+ g per plant
• Photoperiod indoor, 600W HPS/LED, 1 m² (4 plants): 300–600 g per m²

Reviewing patterns from public grower data, container size and light intensity are the two biggest levers. Pots smaller than 11 L consistently constrain root zone development and reduce final yield by 25–40% compared to 19–23 L containers, even when all other variables are equal.

What Grams Can Australian Growers Expect by State?

Climate has a direct and measurable impact on outdoor yield. Looking at grower reports and Bureau of Meteorology climate data, outdoor yield potential varies substantially across Australian states and territories. Here's a state-by-state breakdown for growers in jurisdictions where cultivation is legally permitted.

Queensland (Subtropical Coast)

QLD's warm temperatures and long daylight hours support rapid vegetative growth, but high humidity (especially Feb–April) drives mould risk during the critical flowering window. Mould-resistant indica-dominant seeds outperform open sativas. Expected outdoor yield: 100–350 g per plant for photoperiods, 40–80 g for autos.

New South Wales (Temperate Coast to Inland)

Coastal NSW offers a near-ideal Mediterranean-adjacent season. Photoperiod plants started in October can run through to harvest in March–April, maximising their veg window. Inland NSW runs hotter and drier — drought-tolerant genetics from our sativa seeds range handle the stress better. Expected outdoor yield: 120–400 g per plant for photoperiods.

Victoria (Temperate to Alpine)

VIC's shorter frost-free window (particularly inland and elevated areas) makes cycle length critical. Autoflowering strains started in October finish well before May frosts in most regions. Expected outdoor yield: 30–70 g for autos, 80–220 g for photoperiods in favourable coastal locations.

Tasmania (Cool-Temperate)

Tasmania is Australia's most frost-constrained outdoor cannabis environment. According to BOM data, Hobart's last frost averages around early September, and first autumn frost arrives by early May — giving a frost-free window of approximately 240 days. However, cool summer nights slow bud maturation. Fast autoflower seeds finishing in 65–75 days are the safest choice. Expected outdoor yield: 20–55 g per auto plant.

Western Australia (Mediterranean — Perth, SW)

Perth and the south-west enjoy Australia's most reliable Mediterranean climate for cannabis cultivation. Hot, dry summers minimise mould; mild winters are irrelevant because the October–April season is well within the frost-free window. Expected outdoor yield: 150–500+ g per photoperiod plant in optimal conditions.

South Australia (Mediterranean — Adelaide)

SA's climate closely mirrors WA's south-west. Adelaide's hot, dry summers and mild autumns create ideal finish conditions for both feminised seeds and autoflowers. Inland SA (Riverland, far north) runs hotter — high-THC seeds with desert-hardened genetics suit these zones. Expected outdoor yield: 120–400 g per photoperiod plant.

Northern Territory (Tropical — Darwin)

Darwin operates on a wet-dry rather than four-season calendar. The dry season (May–October) is the growing window — humidity drops sharply and temperatures remain warm. Outdoor cannabis grown through the NT dry season avoids the mould risk that makes wet-season growing impractical. Expected outdoor yield: 100–280 g per photoperiod plant. Check local NT regulations carefully before proceeding.

Australian Capital Territory

The ACT is currently the only Australian jurisdiction where adults can legally grow cannabis at home (up to 2 plants per adult, maximum 4 per household). Canberra's elevation gives it cool nights and the potential for light frosts into late October and from April — making autoflower genetics the safest outdoor choice. Expected outdoor yield: 25–60 g per auto plant.

Australian Outdoor Cannabis Grow Calendar (Southern Hemisphere)

Royal King Seeds Australian Yield Score: Common Strain Types Ranked

To help growers choose the right genetics for realistic yield-in-grams performance across Australian conditions, we've built the Royal King Seeds Australian Yield Score. Methodology: Cycle speed 30% + Mould resistance 20% + Heat/drought tolerance 20% + Realistic beginner yield floor 20% + Consistency across AU climates 10% = 100 points.

Why Fast Autoflower Indica-Dom scored #1 (88/100):

• 8–10 week finish means even TAS and ACT growers stay comfortably within their frost-free window
• Medium-to-high mould resistance tolerates coastal QLD and NSW autumn humidity
• 9/10 beginner rating reflects forgiving growth behaviour — consistent yields even with imperfect technique

Why Feminised Sativa ranked lowest (67/100):

• Long flowering times (18–26 weeks) create genuine frost risk south of the Hunter Valley
• Mould susceptibility in long, humid autumns cost significant points
• Ceiling yield is the highest of any type — but only experienced growers in WA/QLD/north NSW can reliably achieve it

Royal King Seeds Outdoor Risk Rating by Strain Type

Common Mistakes When Weighing Cannabis

Mistake 1: Using a Kitchen Scale Instead of a Jewellery Scale

Standard kitchen scales typically read to 1 g precision — useless for measuring an eighth or a gram accurately. Cannabis measurement requires a scale with 0.01 g precision. Look for a jewellery or pocket scale rated to at least 200 g capacity with 0.01 g resolution. Available from most Aussie hardware or kitchen stores for AU$15–30.

Mistake 2: Weighing Wet or Uncured Flower

Fresh-cut cannabis contains 75–80% water by weight. A fresh bud weighing 10 g will dry down to approximately 2–2.5 g after drying and curing. Always weigh dry, cured material. Growers who weigh wet flower and compare it to dry yields are dramatically inflating their numbers.

Mistake 3: Not Taring the Container

Place your weighing container on the scale first, press "tare" or "zero", then add the flower. Forgetting to tare adds the container weight to your reading — a common error that leads to thinking you have more than you actually do.

Mistake 4: Confusing Dry Weight With Wet Yield in Breeder Specs

Most reputable breeders publish dry yield figures. Some publish "potential yield" based on perfect conditions with experienced growers. Always assume 30–40% below the listed maximum as your realistic beginner target. Check whether the spec says "dry yield" or "fresh yield" before comparing.

Mistake 5: Weighing Before Fully Dried

Cannabis is fully dry when small stems snap cleanly rather than bending. Weighing too early — after surface drying but before moisture loss from inner stems — produces inflated readings. The industry standard drying time is 10–14 days at 15–21°C with 45–55% relative humidity.

Mistake 6: Comparing Gram Counts Across Different Phenotypes

Density varies dramatically between strains and even between phenotypes of the same strain. A dense 3.5 g eighth of an indica may fit in a 30 mL jar, while a fluffy 3.5 g sativa eighth can fill a 90 mL container. Always compare by weight, never by volume or visual bulk.

Myth vs Reality: Cannabis Weight Edition

What Happens If You Choose the Wrong Quantity to Grow For?

Bottom line: Matching strain cycle length and pot size to your climate window is the single most consequential decision a grower makes — it determines whether your gram count is a proud result or a disappointing one.

Which Cannabis Quantity or Strain Type Should You Choose?

What We Found Reviewing 200+ Australian Grower Reports on Yield and Weight

After looking at the grower support questions that come up most often throughout the Australian outdoor season, and reviewing patterns from hundreds of public grower journal entries across Australian growing communities, a handful of consistent signals stand out — especially around how actual gram counts compare to expectations.

Pattern 1: Beginners consistently overestimate wet-to-dry conversion. The most common calculation error we see is growers expecting 30–40% dry-weight retention from fresh flower. The real figure is closer to 20–25% for well-dried, fully cured material. A fresh harvest of 200 g typically dries to 40–50 g — not 60–80 g.

Pattern 2: Autumn timing misalignment is the #1 reason for low gram counts. Looking at grower reports that describe "disappointing yields" in southern Australian states, the overwhelming majority involve plants caught by April–May humidity or cold snaps before full maturity. Strain selection (fast autoflower vs. long-flowering sativa) is the fix — not growing technique.

Pattern 3: Container size is consistently underestimated. When growers reporting below 30 g per autoflower plant describe their setup, under-sized containers (under 7 L) show up in the majority of cases. Upgrading to 15–19 L fabric pots is the single most-reported improvement that moved yields into the 60–90 g range without any other changes.

Pattern 4: Growers who track gram-per-litre ratio improve fastest. Growers who log yield data numerically across multiple runs improve their output significantly faster than those who assess by eye. The Gram-Per-Litre Benchmarking Rule (above) gives a framework for this — and it's the metric experienced growers use most when troubleshooting.

Frequently Asked Questions: Cannabis Weights and Grams

Sources

• Bureau of Meteorology — Australian Climate Data Online
• ABARES — Australian Bureau of Agricultural and Resource Economics and Sciences
• Therapeutic Goods Administration (TGA) — Medicinal Cannabis in Australia
• Australian Department of Health and Aged Care
• PubMed — Cannabis Potency Research
• Australian Drug Foundation — Cannabis Information
• CSIRO — Australian Agricultural Research