Cannabis Weight Measurements Explained: Grams to Ounces

Understanding cannabis weights helps you know what you're buying, verify purchases, and get the best value. Whether you're at a dispensary or verifying with a scale, this guide explains all the standard measurements.

Quick Answer

Cannabis is sold in metric grams but named with imperial fractions. Key weights: 1 gram (single serving), 3.5g (eighth/1/8 oz), 7g (quarter/1/4 oz), 14g (half/1/2 oz), 28g (ounce/oz). An ounce equals 28.35 grams but is usually sold as 28g even. Prices per gram decrease as quantity increases.

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The Complete Weight Chart

For metric system conversions and standards, NIST Metric Program provides official conversion resources.

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Understanding Each Weight

Gram (1g)

The baseline unit.

What it looks like:

• About the size of a grape
• One medium-sized nug
• 2-3 smaller buds

How much it provides:

• 1-2 joints
• 2-3 bowl packs
• Single session for most

Best for:

• Trying new strains
• Occasional users
• Sample purchases

Typical cost: $8-20

Eighth (3.5g)

The most popular purchase size.

What it looks like:

• Fills palm of hand
• 3-5 medium nugs
• 7-10 smaller buds

How much it provides:

• 3-7 joints
• 7-14 bowls
• Week of casual use
• Few days of regular use

Best for:

• Regular consumers
• Weekly purchases
• Trying premium strains

Typical cost: $25-60

Quarter (7g)

Double the eighth.

What it looks like:

• Fills small container
• 6-10 medium nugs
• Noticeable quantity

How much it provides:

• 7-14 joints
• 2 weeks casual use
• Week for daily users

Best for:

• Daily consumers
• Bulk savings starter
• Favorite strains

Typical cost: $45-100

Half Ounce (14g)

Serious quantity.

What it looks like:

• Fills medium jar
• Substantial amount
• Multiple large nugs

How much it provides:

• 14-28 joints
• 3-4 weeks casual
• 2 weeks daily use

Best for:

• Heavy users
• Cost savings
• Stocking up

Typical cost: $80-180

Ounce (28g)

Standard bulk purchase.

What it looks like:

• Fills large jar
• Many nugs
• Significant volume

How much it provides:

• 28-56 joints
• Month or more casual
• 2-4 weeks daily

Best for:

• Maximum savings
• Regular heavy use
• Long-term supply

Typical cost: $150-350

Note: One ounce is typically the maximum legal purchase per day in most recreational states.

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Why Measurements Seem Confusing

Metric vs Imperial

Cannabis uses a hybrid system:

• Grams (metric) for actual weight
• Fractions of ounces (imperial) for naming

This developed from traditional markets using ounces while scales use grams.

Rounding

Technical:

• 1 ounce = 28.3495 grams

In practice:

• Sold as 28 grams even
• Eighths as 3.5g (not 3.54g)
• Slight loss at larger quantities

Slang Variation

Same weights, different names by region:

• Eighth: slice, cut, half-quarter
• Quarter: Q, quad, seven
• Ounce: zip, zone, O, Z

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Pricing and Value

Price Per Gram Comparison

Key insight: Larger quantities = lower cost per gram. An ounce often costs 30-40% less per gram than buying by the eighth.

When to Buy More

Buy larger if:

• You use regularly
• Strain is a favorite
• Storage is proper
• Price break is significant

Buy smaller if:

• Trying new strain
• Occasional use
• Storage concerns
• Budget constraints

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Verifying Your Purchase

Using a Scale

Always verify:

• New dispensary
• Expensive purchases
• Anything that looks light
• Pre-packaged products

How to verify:

1. Tare empty container

2. Add cannabis

3. Compare to labeled weight

Acceptable variance:

• ±0.1g for small purchases
• ±0.3g for ounces
• Significantly under = problem

Visual Estimation

Warning: Visual estimation is unreliable. Density varies hugely.

Denser strains:

• Look smaller than weight
• More compact buds
• Can seem "light"

Fluffy strains:

• Look larger than weight
• Airy, less dense
• Can seem generous

Always use a scale for verification—appearance is deceiving.

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Dispensary vs Street Measurements

Dispensary Standards

Advantages:

• Pre-weighed and sealed
• Licensed and regulated
• Labeled accurately (usually)
• Legal recourse if wrong

Common packaging:

• Exactly 3.5g eighths
• Pre-measured in sealed containers
• Weight printed on label

Traditional Market Issues

Common problems:

• "Generous eighths" (3.0-3.3g)
• Wet cannabis (water weight)
• Heavy stems
• Inconsistent dealers

Why scales matter more:

No regulation, no labels, no recourse.

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Special Considerations

Pre-Rolls

Weight includes:

• Cannabis flower
• Rolling paper
• Filter tip

Typical pre-roll: 0.5g-1g cannabis inside

Verification difficulty: Must break open to weigh contents.

Concentrates

Sold by:

• Half gram (0.5g)
• Gram (1g)
• Eighth (3.5g) for bulk

Much more expensive per gram but much more potent.

Edibles

Measured by:

• THC milligrams (mg)
• Not physical weight

Standard dose: 5-10mg THC

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Common Questions

Why not just use grams?

Historical convention. The imperial fractional system predates legalization and stuck even as metric scales became standard.

Is 3.5g really an eighth?

Close enough. An exact eighth is 3.54g. The 0.04g difference is negligible but technically a small loss to buyers.

What's the most cost-effective purchase?

Usually an ounce, offering 30-40% savings per gram versus buying eighths. Quarter ounces offer the next best value.

How do I know if I'm being shorted?

Use a digital scale. Don't rely on appearance. Weigh immediately after purchase if possible.

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Quick Reference Card

Memorize these:

• 1 gram = 1 gram
• Eighth = 3.5 grams
• Quarter = 7 grams
• Half = 14 grams
• Ounce = 28 grams

Price rule of thumb:

• Eighth: ~$10/gram
• Quarter: ~$8-9/gram
• Ounce: ~$6-8/gram

Verification:

Own a scale. Use it. Every time.

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This guide is for educational purposes. Cannabis laws vary by jurisdiction.