# Dry-weight basis

> Dry-weight basis reports a result per gram of sample with its water removed, while as-received basis reports it per gram as delivered, water included; dry-weight figures are always higher.

- Canonical: https://genetixbay.com/knowledge/glossary/dry-weight-basis.html
- Also written: dry weight basis, dry-weight vs as-received, as-received basis, as received, dry basis, DW basis, wet weight basis
- Glossary category: Lab testing · Evidence: Established
- 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"

A [cannabinoid](https://genetixbay.com/knowledge/glossary/cannabinoid.md) result can be expressed in two ways. As-received (wet basis) divides by the weight of the sample as it arrived, water and all. Dry-weight basis divides by the weight after the water is mathematically removed. Because [cured](https://genetixbay.com/knowledge/glossary/curing.md) flower holds roughly 8-13% water, the same sample reads 9-15% higher on a dry-weight basis.

## In practice

A flower sample at 12% moisture tests 20.0% total [THC](https://genetixbay.com/knowledge/glossary/thc.md) as received. On dry-weight basis: 20.0 / (1 - 0.12) = 22.7%. Neither number is wrong, but comparing one lab's dry-weight figure with another's as-received figure is comparing different things. Some jurisdictions require one basis or the other; a good [COA](https://genetixbay.com/knowledge/glossary/coa.md) always states which, and prints the moisture.

## Units and formula

Dry-weight result = as-received result / (1 - moisture fraction). Moisture fraction is from a loss-on-drying test, e.g. 0.12 for 12%.

## Don't confuse with

- **Water activity**: a measure of how available the water is, not how much there is.
- **Wet (fresh) weight of a harvest**: plant weight before drying, a different context.

## Myth check

Reporting on [dry weight](https://genetixbay.com/knowledge/glossary/dry-weight.md) is legitimate when disclosed. Swapping bases without saying so inflates labels. See [buyer beware](https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.md).

## Related terms

[Moisture correction](https://genetixbay.com/knowledge/glossary/moisture-correction.md), [Potency testing](https://genetixbay.com/knowledge/glossary/potency-testing.md), [COA](https://genetixbay.com/knowledge/glossary/coa.md), [Label inflation](https://genetixbay.com/knowledge/glossary/label-inflation.md), [Water activity test](https://genetixbay.com/knowledge/glossary/water-activity-test.md)

## Read more

- [Buyer beware: potency labels, strain names and other claims that don't hold up](https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.md)

## Sources

1. Schwabe AL, Johnson V, Harrelson J, McGlaughlin ME. 2023. Uncomfortably high: Testing reveals inflated THC potency on retail Cannabis labels. PLOS ONE 18(4):e0282396. https://doi.org/10.1371/journal.pone.0282396