Take the strength printed on your e-liquid, in milligrams per millilitre, and multiply it by the millilitres you get through in a day. At 20mg/ml and 4ml a day, that is 80mg. If you smoke, count cigarettes rather than converting them to milligrams. That number is what a stop smoking adviser uses to size your treatment, and what you step down from.
Most people quitting a vape have never worked this out. They know the flavour and the brand and nothing else, which is a strange position to be in with something you use forty times a day.
The sum, and where the two numbers live
You need two figures and they are both printed on things you already own.
**Strength.** On the bottle or the device, written as mg/ml, sometimes as a percentage. 2% is the same as 20mg/ml. In the UK, e-liquids are restricted "to a nicotine strength of no more than 20mg/ml", so 20 is the legal ceiling for a consumer product.
**Volume.** How much liquid you actually get through. Refill bottles are capped at 10ml, and tanks at 2ml, so counting refills is easier than it sounds. If you fill a 2ml tank twice a day, that is 4ml.
Multiply them. That is your daily milligrams, and it is the number to write down.
If you use disposables
The sum still works, it is just hidden.
A legal UK disposable holds no more than 2ml at no more than 20mg/ml, so one device a day is up to 40mg. Two a day is up to 80mg. Work in devices per week if that is easier, then divide by seven.
Two honest caveats. Puff counts on the packaging are not a dose, they are a marketing number, so ignore them for this. And if your device visibly holds far more liquid than a 2ml tank, it sits outside the UK limits and you cannot rely on anything printed on it, including the strength.
Cigarettes: count them, do not convert them
You will find charts online converting cigarettes to milligrams. We are not going to give you one, because how much nicotine you take from a cigarette depends on how you smoke it, and a number that precise would be invented.
Count instead. Cigarettes a day, over a normal week rather than a good one. Note whether that changes at weekends, and roughly how soon after waking the first one happens. An adviser will ask you both of those, and they are more useful than any conversion table.
If you smoke and vape, do both counts and take them both in.
What the number is actually for
Three things, and none of them is judging you.
**Sizing your treatment.** The single most common reason nicotine replacement therapy "does not work" is that the dose was too low, guessed off the back of a box by someone who did not want to seem greedy about it. Handing an adviser a real number solves that in one appointment. There is more on the dosing in [patches, gum, vapes: what actually helps](/guides/nicotine/nrt-vapes-and-what-actually-helps-you-quit).
**Stepping down.** Vape strengths come in steps, which is a dial smokers never had. Going from 20mg/ml to 12 to 6 to 3 is a real route, and it only means anything if you know where you started and keep the millilitres roughly steady. Dropping the strength and then vaping twice as much is a very easy way to run in place.
**Seeing the trend.** Once you have a daily figure, a fortnight of it tells you whether you are drifting up. Most people find they are.
The moment the number lands
Be ready for this. People who have never smoked and started on disposables often work this out and feel slightly sick.
That reaction is worth something, but not much, and only for about a day. Then it turns into shame, and shame is not a quit plan. The number is a measurement, in the same way as a mileage reading. It tells you the size of the job. It says nothing about your character.
If it is much bigger than you expected, that is an argument for getting free help rather than doing this alone, not an argument that you are past helping.
A week of counting
- **Write down the strength** on whatever you are using now, in mg/ml.
- **Count the liquid**, in millilitres or in devices, for seven days. Not your best week. This one.
- **Count cigarettes separately** if you smoke as well.
- **Do the multiplication** and write the daily figure somewhere you will find it.
- **Take it to a stop smoking adviser.** It is free, and it is the difference between a guess and a dose. See [what NHS stop smoking services offer](/guides/nicotine/nhs-stop-smoking-services-and-what-they-offer).
That is the whole exercise. It takes a week and no effort, and it can happen while you are still using, before you have committed to a date.
If you have already picked a date
Good. Do the counting anyway, in the days before. Walking into a first appointment with a number is the difference between an adviser sizing your treatment and an adviser asking you to estimate, at the exact moment you are least able to.
And if the thing you are quitting is a vape rather than cigarettes, the counting matters more, not less, because there is no natural unit. A cigarette ends. A device does not, which is the whole problem, and it is covered in [why quitting vaping is different](/guides/nicotine/why-quitting-vaping-is-different).
Common questions
Is 20mg/ml a lot?
It is the highest strength that can legally be sold in the UK, since e-liquids are restricted to no more than 20mg/ml. Whether that adds up to a lot depends entirely on how much you get through, which is why the millilitres matter as much as the strength.
How do I convert cigarettes into milligrams?
You do not, at least not reliably. The dose you take from a cigarette depends on how deeply and how often you draw on it, so any single conversion figure is made up. Count cigarettes a day and let an adviser work with that.
Does the strength on a disposable tell me the dose?
It tells you the concentration, not the dose. Multiply it by the liquid the device holds, which for a legal UK product is no more than 2ml. Puff counts on the box are not a measure of nicotine.
Should I just drop straight to a lower strength?
Ask an adviser first, and keep an eye on your millilitres if you do. Dropping the strength while unconsciously doubling how much you vape leaves your daily total exactly where it was, and it is the most common way a step-down quietly fails.
I have never smoked. Does any of this apply?
The counting does, and it is arguably more useful to you, because none of the standard advice was written for someone who started on vapes. [How to stop smoking or vaping](/guides/nicotine/how-to-stop-smoking-or-vaping) sets out which parts transfer.
Sources
- [GOV.UK, E-cigarettes: regulations for consumer products](https://www.gov.uk/guidance/e-cigarettes-regulations-for-consumer-products). The 20mg/ml strength limit, the 2ml tank limit and the 10ml refill container limit.
- [NHS Stop Smoking Services help you quit](https://www.nhs.uk/live-well/quit-smoking/nhs-stop-smoking-services-help-you-quit/). What a free service supplies and how to be referred.
- [NHS: using e-cigarettes to stop smoking](https://www.nhs.uk/live-well/quit-smoking/using-e-cigarettes-to-stop-smoking/). Where vaping sits against smoking, and who it is and is not recommended for.
