Shortfill e-liquids come without nicotine, with space left in the bottle to add it yourself using nicotine shots (also called nic shots). This calculator tells you how many shots to add to reach the strength you want, and what strength you'll end up with. Enter your numbers below, and read on for how it works.
Nic shot calculator
How the calculator works
A nicotine shot is a 10ml bottle of unflavoured nicotine liquid. In the UK, nicotine e-liquid can be no stronger than 20mg/ml and can't be sold in containers larger than 10ml, which is why nicotine shots come in 10ml bottles of 18mg/ml or 20mg/ml.
When you add a shot to a shortfill, the nicotine spreads through the whole bottle, so the final strength depends on how much liquid there is in total. The calculator uses this formula:
Final strength = (number of shots × 10ml × shot strength) ÷ (shortfill ml + number of shots × 10ml)
It works backwards from the strength you want to tell you how many shots you need. Because shots only come in whole bottles, it also shows the strength you'll get with the whole number of shots either side.
Common shortfill and nic shot combinations
| Shortfill | Shots | With 18mg/ml shots | With 20mg/ml shots |
|---|---|---|---|
| 50ml | 1 | 3mg/ml (60ml) | 3.3mg/ml (60ml) |
| 50ml | 2 | 5.1mg/ml (70ml) | 5.7mg/ml (70ml) |
| 100ml | 1 | 1.6mg/ml (110ml) | 1.8mg/ml (110ml) |
| 100ml | 2 | 3mg/ml (120ml) | 3.3mg/ml (120ml) |
| 100ml | 4 | 5.1mg/ml (140ml) | 5.7mg/ml (140ml) |
Shortfill bottles usually leave just enough room for the shots needed to reach around 3mg/ml. A 50ml shortfill often comes in a 60ml bottle, for example. For a higher strength you'll need a larger empty bottle to mix in.
Can you make 6mg/ml or stronger from a shortfill?
You can get close, but it takes a lot of shots. To reach 6mg/ml with 18mg/ml shots, you need one shot for every 20ml of shortfill: five shots for 100ml. The more shots you add, the more the flavour is diluted, so many vapers who want higher strengths use ready-mixed 10ml e-liquids or nic salts instead.
The strongest you can make is always below the strength of the shot itself. With 18mg/ml shots, adding more and more shots gets you closer to 18mg/ml but never reaches it.
How to add nic shots to a shortfill
- Remove the cap and pull the nozzle tip off the shortfill bottle.
- Open your nicotine shots and squeeze them into the shortfill.
- Replace the nozzle and cap firmly.
- Shake the bottle well for a minute or two so the nicotine mixes evenly through the liquid.
Our step-by-step guide to mixing your own shortfill covers this in more detail, and our guide to opening vape juice bottles helps with stubborn caps and nozzles. You can find nicotine shots here.
Using the calculator to cut down
If you're reducing your nicotine, the calculator helps you plan each step down, for example from 6mg/ml to 3mg/ml to 1.5mg/ml. Our guide to quitting vaping explains how to step down gradually.
Handling nicotine shots safely
Nicotine shots contain concentrated nicotine. Mix on a flat surface away from children and pets, and close the bottles properly afterwards. If you get nicotine liquid on your skin, the Royal College of Nursing's guidance on e-liquid exposure advises washing it off thoroughly with soap and water. If a child swallows any, follow the NHS advice on poisoning and call 999 or go to A&E.
Frequently asked questions
How many nic shots do I need for 100ml to make 3mg?
Two 18mg/ml shots in 100ml of shortfill gives 120ml at 3mg/ml.
How many nic shots for 100ml to make 6mg?
Five 18mg/ml shots, which gives 150ml at 6mg/ml. You'll need a larger empty bottle, because most 100ml shortfills only have room for two shots.
How much nicotine shot should I add to 50ml?
One 10ml shot of 18mg/ml makes 60ml at 3mg/ml. Two shots make 70ml at about 5.1mg/ml.
How many nic shots for 100ml to make 20mg?
You can't. Nicotine shots are 20mg/ml at most, so adding them to a shortfill always gives a weaker result. For 20mg/ml, use a ready-mixed 20mg/ml e-liquid or nic salt instead.