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What does the mg number on a CBD bottle mean?

A figure like 3,000 mg is usually the total CBD in the bottle. The strength that matters is mg per mL, found by dividing the total by the volume.

Facts checked 13 November 20262 min readHow we research

A large figure such as 1,000 mg or 3,000 mg on a CBD bottle is usually the total amount of CBD in the whole bottle. How strong the oil is depends on the strength in milligrams per millilitre (mg/mL), which you get by dividing the total by the bottle’s volume.1

How do you work out the strength?

strength (mg/mL) = total CBD (mg) ÷ bottle volume (mL)

Bottle Total CBD Strength
30 mL 3,000 mg 100 mg/mL
30 mL 600 mg 20 mg/mL

The bottles are the same size, and one is five times as strong. For comparison, the registered medicine Epidyolex is 100 mg/mL in a 100 mL bottle.2

How does that relate to a dose?

volume (mL) = dose (mg) ÷ strength (mg/mL)

If a prescriber has set 50 mg and the oil is 100 mg/mL, that is 0.5 mL. With a 20 mg/mL oil the same dose is 2.5 mL. Use the measuring device supplied. This arithmetic is for reading a dose your prescriber has already set, not a way to choose one. The dose calculator does the sums.

Is the number accurate?

For prescribed products in Australia, the standard TGO 93 requires each active ingredient to be within 90% to 110% of the stated amount.1 Unregulated products are less reliable. In a 2024 United States study of 202 products bought online, 74% were at least 10% off their labelled CBD content.3 See does CBD oil contain what the label says?

What does a ratio such as 20:1 mean?

The proportion of CBD to THC. A 20:1 oil with 100 mg/mL of CBD has 5 mg/mL of THC. That makes it a Schedule 8 product, not a CBD-only one, because a CBD-only product needs CBD to be 98% or more of the cannabinoids.4

What else must an Australian label show?

A prescribed cannabis medicine must show each active ingredient and its amount, the dosage form, the quantity, a batch number, an expiry date, storage conditions and the sponsor’s details.1 THC only has to be declared once it reaches 1.0% of the product, so “no THC listed” is not the same as “no THC”.1

Does a bigger number mean a better product?

No. It means more CBD per bottle. It says nothing about quality, and the prescriber sets the dose.

Read the full guide: how to read a CBD label.

Footnotes

  1. Australian Government. Therapeutic Goods (Standard for Medicinal Cannabis) (TGO 93) Order 2017, compilation of 6 December 2022, sections 4, 12, 15 and 17. https://www.legislation.gov.au/F2017L00286/latest/text ↩ ↩2 ↩3 ↩4

  2. Therapeutic Goods Administration. Epidyolex (cannabidiol) Australian Product Information, version published with the AusPAR, January 2021 (may have been superseded). https://www.tga.gov.au/sites/default/files/auspar-cannabidiol-210115-pi.pdf ↩

  3. Gidal BE, et al. Product labeling accuracy and contamination analysis of commercially available cannabidiol product samples. Frontiers in Pharmacology, 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC10982813/ ↩

  4. Australian Government. Therapeutic Goods (Poisons Standard, October 2026) Instrument 2026, Schedule 3 and Schedule 4 cannabidiol entries. https://www.legislation.gov.au/F2026L01327/asmade/2026-09-30/text/original/pdf ↩

This page is general information, not medical or legal advice. Laws and evidence change; we show the date we last checked the facts at the top of every page. Talk to your doctor or pharmacist before starting, stopping or changing any medicine.

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