Nicotine Strength Explained: mg/mL, Nic Salt Labels and the NZ Limits
The nicotine figure on an e-liquid label is the single most misread number in vaping. The same bottle can be described as "25 mg", "2.5%" or "14.26 mg/mL nicotine" depending on who is talking. This guide explains what each figure means, how New Zealand requires it to be shown, and how to compare products. It is current as of September 2026.
The unit: milligrams per millilitre
Nicotine strength is a concentration: how many milligrams of nicotine are in each millilitre of liquid. A 30 ml bottle at 12 mg/mL contains 360 mg of nicotine in total. In New Zealand the concentration must be shown on the label in mg/mL. Showing it only as a percentage is not permitted.
Percentages and mg/mL
Overseas labels often use percentages. The conversion is simple: 1% is approximately 10 mg/mL, so 2% is about 20 mg/mL and 5% is about 50 mg/mL. The approximation works because e-liquid has a density close to 1 g/mL.
Why a nicotine salt bottle can show two numbers
In a nicotine salt e-liquid, the nicotine is bonded to an acid (commonly benzoic acid). The salt weighs more than the nicotine inside it. So a label can state either the concentration of the salt or the concentration of the nicotine, and the two are different. For example, one of the e-liquids we make, Tall Boys Salts, is labelled "25 mg/mL nic salts (14.26 mg/mL nicotine concentration)": 25 mg of nicotine salt per millilitre delivers about 14 mg of nicotine per millilitre.
This is exactly the confusion the Ministry of Health resolved in 2023. The original regulation set a limit of 50 mg/mL for nicotine salts, which some businesses read as 50 mg/mL of nicotine. The clarified rule sets the limit as 28.5 mg/mL of nicotine for reusable products using nicotine salts, which corresponds to 50 mg/mL of nicotine salt. When you see "50 mg" or "5%" on an imported salt product, that is the salt figure at the NZ maximum, not a higher-than-legal product.
The legal maximums in New Zealand
| Product | Maximum |
|---|---|
| Freebase nicotine e-liquid | 20 mg/mL nicotine |
| Nicotine salt e-liquid (reusable devices) | 28.5 mg/mL nicotine (50 mg/mL nicotine salt) |
Typical strengths by device type
- Sub-ohm tanks (direct-to-lung): freebase at 3 or 6 mg/mL. Higher strengths are harsh at these power levels.
- Refillable pod kits (mouth-to-lung): nicotine salts anywhere from 6 to 28.5 mg/mL nicotine, or freebase at 12 to 20 mg/mL.
- Prefilled pod vapes: most are supplied at or near the salt maximum of 28.5 mg/mL nicotine.
- Nicotine free: 0 mg/mL versions of most ranges exist for people who have stepped down.
How the two nicotine types feel different is covered in our Nic Salts vs Freebase guide.
Comparing two products fairly
- Find the mg/mL figure. If a label gives a percentage, multiply by 10.
- For a salt product, check whether the figure is the salt or the nicotine. If only the salt figure is shown, multiply by roughly 0.57 to get the nicotine figure.
- Compare nicotine to nicotine. A "25 mg salt" bottle (about 14 mg/mL nicotine) is weaker than an "18 mg/mL nicotine" freebase bottle, despite the bigger number.
Reading a Vapourium label
Our nicotine salt labels state both figures so there is no ambiguity, and our freebase labels state the nicotine concentration in mg/mL. Every bottle also carries the required bilingual warning, the ingredients, a batch identifier and a generic flavour name. The full list of ranges we manufacture is on Made by Vapourium.
Related reading
Sources: Smokefree Environments and Regulated Products Regulations 2021 (as amended 2023); Ministry of Health, Proposed regulation to clarify allowable nicotine concentration for some vaping products, 12 June 2023.