# Eighth

> An eighth is one-eighth of an ounce of cannabis, sold as 3.5 grams; it is the standard retail unit for flower in North America.

- Canonical: https://genetixbay.com/knowledge/glossary/eighth.html
- Also written: 8th, an eighth, eighths, 3.5, 3.5 g
- Glossary category: Grower slang and culture
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

An eighth is 1/8 of an avoirdupois ounce, 3.54 g, rounded to 3.5 g in retail. It is the most common retail size for flower in North America, and prices are often quoted "per eighth".

## In practice

Because flower keeps losing moisture after packaging, an eighth sealed at the right moisture can weigh slightly less weeks later, and one packed too wet will dry in the jar. Regulated markets set tolerances for net weight; check local rules. For a home grower, an eighth is a handy unit for sample jars and for comparing cure results between batches.

## Units and formula

| Slang | Nominal weight | Metric |
|---|---|---|
| Gram | 1 g | 1 g |
| Eighth | 1/8 oz | 3.5 g (exact: 3.54 g) |
| Quarter | 1/4 oz | 7 g |
| Half | 1/2 oz | 14 g |
| Ounce (zip, O) | 1 oz | 28 g (exact: 28.35 g) |
| QP | 1/4 lb (4 oz) | 113 g |
| Pound (elbow, LB) | 1 lb (16 oz) | 454 g (exact: 453.6 g) |

Retail rounds an eighth to 3.5 g and an ounce to 28 g.

## Don't confuse with

- **Quarter**: 7 g, two eighths.
- **Metric 5 g packs**: some markets sell in round metric units instead.

## Related terms

[Gram](https://genetixbay.com/knowledge/glossary/gram.md), [Ounce](https://genetixbay.com/knowledge/glossary/ounce.md), [QP](https://genetixbay.com/knowledge/glossary/qp.md), [Elbow](https://genetixbay.com/knowledge/glossary/elbow.md)