To compare CBD e-liquid strengths, check both the total CBD in the container and its volume. A label saying 1000 mg does not tell you the concentration until you know how many millilitres it contains.
This guide is for adults who already smoke or vape. It explains label quantities, not a recommended amount to inhale.
How to calculate CBD concentration
Total CBD in mg / liquid volume in ml = CBD concentration in mg/ml.
For example, 500 mg in a 10 ml bottle is 50 mg/ml. The same 500 mg in a 30 ml bottle is about 16.7 mg/ml. The bottles contain the same total CBD, but different amounts per millilitre.
Compare 500 mg, 1000 mg, 2000 mg, 2500 mg and 5000 mg
| Total CBD | In 10 ml | In 30 ml |
|---|---|---|
| 500 mg | 50 mg/ml | 16.7 mg/ml |
| 1000 mg | 100 mg/ml | 33.3 mg/ml |
| 2000 mg | 200 mg/ml | 66.7 mg/ml |
| 2500 mg | 250 mg/ml | 83.3 mg/ml |
| 5000 mg | 500 mg/ml | 166.7 mg/ml |
If a label uses a percentage, check how the manufacturer defines it. The calculation above uses milligrams and millilitres. A percentage based on weight needs different information.
Concentration does not tell you the amount per puff
The amount delivered depends on the device and how it is used. Bottle volume and concentration alone cannot establish how much CBD you inhale or absorb. A higher mg/ml figure describes a more concentrated liquid. It does not establish a better result.
Oral and inhaled CBD are delivered differently, so an oral serving cannot be converted into a puff recommendation using this table. See Millar and colleagues' review of CBD delivery for the differences between delivery routes.
What to check when comparing labels
- Read the total CBD quantity and the container volume together.
- Compare mg/ml using the same units for each product.
- Check the intended use and device compatibility in the product instructions.
- Keep container content, liquid concentration and the amount delivered per puff separate.
