Picking a nicotine strength is the single most important choice a new vaper makes, and the one most often got wrong in both directions. Too low and the craving never settles; too high and it feels harsh. This guide explains the numbers and gives a sensible starting point.
mg/ml and %: the same thing, written two ways
UK e-liquid strength is shown either in milligrams per millilitre (mg/ml) or as a percentage. They describe the identical thing:
- 3mg/ml = 0.3%
- 6mg/ml = 0.6%
- 10mg/ml = 1.0%
- 12mg/ml = 1.2%
- 18mg/ml = 1.8%
- 20mg/ml = 2.0%
So a "2% nic salt" and a "20mg/ml nic salt" are the same strength. Multiply the percentage by ten to get mg/ml.
No nicotine e-liquid sold legally in the UK may exceed 20mg/ml (2%). Any product advertised above that strength is not compliant. This limit is set by the Tobacco and Related Products Regulations 2016.
Why the same number feels different: salt vs freebase
A 20mg/ml nicotine salt and a 20mg/ml freebase both contain the same amount of nicotine, but they feel very different. Nicotine salts are smoother on the inhale and are generally felt more quickly, which is why higher strengths (10mg/ml and 20mg/ml) are almost always sold as salts and used in pods and MTL kits.
Freebase at the same strength gives a much firmer throat hit, so freebase is more common at lower strengths (3mg/ml and 6mg/ml) and in higher-powered sub-ohm devices. If a strength feels harsh in a pod, a salt version of the same number will usually feel smoother. The full breakdown is in our e-liquid types guide.
A starting-point reference table
The established principle, reflected in NHS guidance, is to start at a level that matches how much and how often you used to smoke, then adjust. The table below is a common industry starting point, not a prescription, everyone is different, and it is easy to step up or down after a few days.
| Previous smoking habit | Freebase | Nic salt | Typical device |
|---|---|---|---|
| Light / social (1–5 a day) | 3–6mg/ml | 10mg/ml | Pod or MTL |
| Moderate (roughly 6–15 a day) | 12mg/ml | 10mg/ml | Pod or MTL |
| Heavy (15–20+ a day) | 18mg/ml | 20mg/ml | Pod or MTL |
| Sub-ohm / direct-to-lung | 3mg/ml | Not suited | Sub-ohm tank |
High-wattage sub-ohm kits deliver a lot of vapour per puff, so they are paired with low strengths, usually 3mg/ml. Using a 20mg/ml liquid in a sub-ohm device delivers far more nicotine than intended and will feel unpleasant. Keep high strengths to low-power pods and MTL devices.
Adjusting after you start
Give any new strength a couple of days. Signs you may be too low: still craving, vaping constantly, reaching for a cigarette. Signs you may be too high: light-headedness, a harsh or peppery throat, headaches. Step down or up one band and reassess. Many people settle lower over time.
If you're coming from disposables
Most single-use vapes sold before the June 2025 ban were 20mg/ml nicotine salt. If you are moving to a refillable pod kit, a 20mg/ml salt in the same flavour family is the closest match. Our switch-over guide walks through it.
Sources
- The Tobacco and Related Products Regulations 2016, reg. 36 (20mg/ml maximum strength): legislation.gov.uk/uksi/2016/507/regulation/36
- NHS, "Vaping to quit smoking" (start at a level matching how much and how often you smoke): nhs.uk/better-health/quit-smoking
- MHRA / GOV.UK, "E-cigarettes: regulations for consumer products": gov.uk/guidance/e-cigarettes-regulations-for-consumer-products
This guide gives factual information about the products we sell. It is not medical or stop-smoking advice, and the table is a general starting point rather than a recommendation for any individual. If you have questions about your health or about quitting smoking, the NHS Better Health service is the right place to start.