How Many Nic Shots Do I Need? A Complete Shortfill Mixing Guide

Nicotine shots make it easy to add nicotine to a shortfill, but working out how many you need isn't always quite as obvious. The answer depends on how much nicotine-free e-liquid you're starting with, the strength of your nic shot and the nicotine strength you want to end up with.

For one of the most common combinations, the calculation is simple: add one 10ml 18mg nic shot to a 50ml shortfill and you'll have 60ml of e-liquid at approximately 3mg/ml.

The same principle applies to larger bottles:

Starting shortfill	18mg nic shots	Finished amount	Final nicotine strength
50ml	1 × 10ml	60ml	3mg/ml
100ml	2 × 10ml	120ml	3mg/ml
200ml	4 × 10ml	240ml	3mg/ml

 

There's one important catch with larger shortfills: the bottle needs enough empty space for the nic shots you're adding.

A 50ml shortfill commonly comes in a 60ml bottle, while a 100ml shortfill may come in a 120ml bottle. If you want to add four shots to 200ml of e-liquid, however, you'll need capacity for the finished 240ml mixture. Never try to force more liquid into a bottle than it can hold.

In this guide, we'll explain the calculations, show you how to add your nic shots correctly and help you choose the right type for your e-liquid.

What Is a Nic Shot?

A nicotine shot, usually shortened to nic shot, is a small bottle of nicotine-containing e-liquid designed to be added to a larger quantity of nicotine-free vape juice.

In the UK, you'll commonly find nic shots supplied in 10ml bottles, with 18mg/ml being a particularly popular strength for mixing with shortfills. Nic shots can also differ in their nicotine type and VG/PG formulation.

For example, at UK Vape Supply you'll find options including:

• 50/50 freebase nic shots for a balanced VG/PG mix.
• Higher-VG freebase nic shots for suitable high-VG shortfills.
• 50/50 nic salt shots for vapers who prefer salt nicotine.

We'll look at which one to choose later. First, it's worth understanding what the number on the bottle actually means.

What Does 18mg Mean on a Nic Shot?

An 18mg nic shot contains 18mg of nicotine per millilitre of e-liquid.

Because a standard shot contains 10ml:

18mg/ml × 10ml = 180mg of nicotine in the whole nic shot.

That doesn't mean your finished shortfill becomes 18mg/ml when you add the shot. The nicotine is diluted across all of the e-liquid in the finished bottle.

If you add that 180mg of nicotine to 50ml of nicotine-free shortfill, you'll have:

50ml shortfill + 10ml nic shot = 60ml total e-liquid

The 180mg of nicotine is now distributed throughout those 60ml:

180mg ÷ 60ml = 3mg/ml

That's why one 18mg shot added to 50ml of shortfill produces approximately 60ml of 3mg e-liquid.

Why Do 100ml Shortfills Need Two Nic Shots for 3mg?

The same calculation scales neatly with a 100ml shortfill.

Two 10ml 18mg nic shots contain a combined 360mg of nicotine. Add them to 100ml of nicotine-free e-liquid and the finished volume becomes 120ml.

360mg ÷ 120ml = 3mg/ml

So:

100ml shortfill + two 10ml 18mg shots = 120ml at approximately 3mg/ml.

This is why you'll often see 100ml shortfills supplied in bottles with around 20ml of spare capacity.

What About a 200ml Shortfill?

Mathematically, four 10ml 18mg nic shots added to 200ml of nicotine-free e-liquid gives you 240ml at 3mg/ml. The bigger consideration is where those additional 40ml are going to go.

If the original bottle doesn't have 40ml of spare capacity, you won't be able to mix everything in that bottle. Check the actual bottle capacity before adding anything.

You may need a suitably sized clean mixing bottle rather than trying to squeeze additional nic shots into a full shortfill bottle.

UK Vape Supply Tip: Don't judge spare capacity by looking at the bottle. Check how much e-liquid it contains and the total bottle capacity before you start mixing.

What If I'm Using a 20mg Nic Shot?

A 20mg/ml nic shot contains slightly more nicotine than an 18mg/ml shot, so the final strength will be slightly higher if you use the same quantity.

One 10ml 20mg shot contains 200mg of nicotine.

Added to a 50ml shortfill:

200mg ÷ 60ml = approximately 3.33mg/ml

So one 20mg shot in 50ml doesn't produce exactly 3mg. It produces approximately 3.3mg/ml.

Likewise, two 10ml 20mg shots added to a 100ml shortfill give:

400mg ÷ 120ml = approximately 3.33mg/ml

This is why it's important to check the strength printed on your nic shot rather than assuming every 10ml bottle produces exactly the same result.

Can I Make a 6mg Shortfill with Nic Shots?

You can create stronger mixtures using nic shots, but this is where the calculation becomes less intuitive.

Simply doubling the number of 18mg shots doesn't turn a 3mg mixture into 6mg, because every extra shot adds another 10ml to the total volume.

For example, if you add two 10ml 18mg shots to 50ml of shortfill, you have:

• 50ml nicotine-free e-liquid.
• 20ml of nic shots.
• 360mg total nicotine.
• 70ml total finished e-liquid.

That gives a final strength of approximately 5.14mg/ml, not 6mg/ml.

To turn 50ml of nicotine-free liquid into a true 6mg/ml finished mixture using an 18mg/ml nic shot, you'd need approximately 25ml of nic shot, giving you 75ml of finished e-liquid.

That presents another practical issue: a typical 60ml bottle containing a 50ml shortfill won't have anywhere near enough room.

Why Higher Nicotine Shortfills Need More Planning

Shortfills are particularly convenient for producing lower nicotine strengths such as 3mg, but they become less straightforward as the target strength increases.

Adding more nic shots:

• Increases the amount of nicotine.
• Increases the total volume of e-liquid.
• Changes the final VG/PG ratio.
• Requires additional bottle capacity.

This is why we'd always recommend working out the finished strength and volume before adding multiple nic shots, rather than assuming that twice as many shots automatically means twice the nicotine strength.

If you regularly vape at higher nicotine strengths, a pre-mixed 10ml nic salt or freebase e-liquid may also be a more practical option than trying to convert a large shortfill.

How to Add a Nic Shot to a Shortfill

Once you know how many shots you need, actually mixing your shortfill is straightforward.

1. Check Your Shortfill and Nic Shot

Before opening anything, confirm:

• How much nicotine-free e-liquid is in the shortfill.
• The total capacity of the bottle.
• The strength of your nic shot.
• How many shots you're planning to add.

It's worth checking twice. Once nicotine has been added, you can't simply remove it again if you've miscalculated.

2. Remove the Shortfill Nozzle

Unscrew the cap and carefully remove the dispensing nozzle or nib from the shortfill bottle. Some bottles are easier to open than others. Avoid using sharp tools that could slip, damage the bottle or cause injury.

3. Add the Nic Shot

Remove the cap from your nic shot and carefully empty the required amount into the shortfill. If you're adding a full 10ml shot to a standard 50ml shortfill with sufficient bottle space, you can empty the entire nic shot into the bottle.

If your calculation requires a partial nic shot, you'll need to measure the amount accurately rather than estimating it by eye.

4. Replace the Nozzle and Cap

Once you've added the nicotine, securely replace the shortfill nozzle and screw the cap back on. Make sure everything is properly fitted before moving on to the next step.

5. Shake the Bottle Thoroughly

Give the bottle a thorough shake so the nic shot is evenly mixed throughout the e-liquid.

This is particularly important with thicker, higher-VG liquids. Turn and invert the bottle as you shake it rather than giving it a couple of quick movements and assuming it's mixed.

6. Let Any Bubbles Settle

Shaking can introduce lots of small air bubbles into the e-liquid. Giving the bottle a few minutes to settle can make it easier to fill your vape afterwards.

You don't need to steep a shortfill for days simply because you've added a nic shot. The important part is making sure the nicotine has been thoroughly mixed throughout the liquid.

From the UK Vape Supply team: Mix the entire bottle before filling your vape. Adding a nic shot and immediately taking liquid from the top of an unmixed bottle defeats the point of calculating a consistent final nicotine strength.

Which Nic Shot Should I Use?

Getting the amount right is only part of the job. Nic shots are available with different VG/PG ratios and nicotine types, and your choice can affect the finished e-liquid.

The best approach is to think about the shortfill you're adding it to and the vape you'll use with the finished mixture.

50/50 or High-VG Nic Shot?

Adding a nic shot changes the overall VG/PG ratio because the shot itself contains VG and PG. If you're using a 50VG/50PG pod-fill shortfill, a 50/50 nic shot is the natural choice if you want to keep the finished mixture close to that balance.

For a traditional higher-VG shortfill intended for sub-ohm vaping, a higher-VG nic shot can help maintain a thicker finished liquid.

This doesn't mean that adding one 50/50 shot to a high-VG shortfill suddenly makes the entire bottle unsuitable for vaping. It simply shifts the final ratio. The more nic-shot liquid you add, the greater that effect becomes.

If you're not sure what ratio your device needs, read our What VG/PG Ratio Does My Vape Need? guide before choosing your nic shot.

Freebase or Nic Salt Nic Shot?

You may also have a choice between freebase nicotine and nicotine salt shots.

Freebase is the more traditional form of nicotine used in e-liquid and generally provides a more noticeable throat hit. Nic salts typically provide a smoother nicotine experience at an equivalent strength.

Neither is automatically the better option. Your choice comes down to the experience you prefer, the shortfill you're mixing and the device you'll use.

For a fuller explanation of the difference, our Nic Salts, Freebase or Shortfills: Which E-Liquid Is Right for You? guide covers nicotine formats in more detail.

Does Adding a Nic Shot Change the VG/PG Ratio?

Yes. Your finished VG/PG ratio is determined by all of the liquid in the bottle, including the nic shot.

As a simple example, imagine you have a 50ml shortfill at 70VG/30PG and add a 10ml 50/50 nic shot. The finished 60ml mixture will no longer be exactly 70VG/30PG because you've introduced additional VG and PG in equal proportions.

For many vapers, that relatively small change won't create a problem. It becomes more important when:

• You're adding several nic shots.
• Your device has more specific e-liquid requirements.
• You're deliberately trying to maintain a very high-VG mix.
• You're mixing a 50/50 pod-fill liquid and want to preserve its balance.

This is another reason to choose your nic shot based on the finished mixture rather than simply grabbing any 18mg bottle.

Common Mistakes When Mixing Nic Shots

The process itself is easy, but a few mistakes can leave you with the wrong nicotine strength or an e-liquid that isn't ideal for your device.

Assuming One Nic Shot Always Makes 3mg

It doesn't.

One 10ml 18mg shot produces 3mg/ml when added to 50ml of nicotine-free e-liquid, because the finished volume is 60ml. Add the same shot to a different amount of e-liquid and the final strength changes.

Confusing Nic Shot Strength with Finished Strength

An 18mg nic shot is 18mg/ml before dilution. It doesn't make the entire shortfill 18mg/ml. Always calculate nicotine across the finished volume.

Adding Too Many Shots for the Bottle

The maths might tell you that you need several nic shots, but you still need somewhere to put them. Check the bottle capacity first. If there isn't enough room, don't overfill it.

Forgetting About VG/PG

The nic shot becomes part of your finished e-liquid, so its VG/PG formulation matters too. This is particularly worth considering if you're adding multiple shots or your coil has specific e-liquid requirements.

Not Shaking the Shortfill Properly

Once you've added nicotine, it needs to be thoroughly mixed throughout the bottle. Don't add a shot and immediately fill your pod or tank without mixing the liquid first.

Adding Nicotine to E-Liquid That Already Contains It

Nic shots are intended for use with suitable nicotine-free e-liquids such as 0mg shortfills. Don't automatically add a shot to a bottle simply because there is spare room. Check the existing nicotine strength first.

Can You Vape a Shortfill Without Adding a Nic Shot?

Yes. If your shortfill is supplied at 0mg, you can vape it without adding nicotine.

Nic shots aren't required to activate the flavour or make a shortfill suitable for vaping. The spare space in the bottle simply gives you the option to add nicotine if you want it.

For vapers who no longer use nicotine, the shortfill can remain at 0mg.

Can You Vape a Nic Shot on Its Own?

Nic shots are designed as mixing products, rather than standalone flavoured e-liquids.

They're highly concentrated compared with the finished nicotine strengths commonly created in shortfills and are normally unflavoured. Use them for their intended purpose: adding a measured amount of nicotine to a suitable nicotine-free e-liquid.

Handling and Storing Nic Shots

Nicotine-containing e-liquid needs to be handled carefully. 

When you're mixing:

• Keep nic shots and mixed e-liquid away from children and pets.
• Avoid getting nicotine-containing liquid on your skin and wash it off promptly if you spill any.
• Keep bottles securely closed when you're not using them.
• Follow the storage instructions provided with the product.
• Store e-liquids away from excessive heat and direct sunlight.

It's also worth doing your mixing on a clean, stable surface. Nic shots are small bottles, but a spill can quickly become messy when you're trying to empty several into a larger shortfill.

Shortfill Mixing Doesn't Need to Be Complicated

For most vapers using standard 18mg nic shots, the most useful numbers are easy to remember:

50ml + one 10ml 18mg nic shot = 60ml at 3mg/ml.

100ml + two 10ml 18mg nic shots = 120ml at 3mg/ml.

For larger bottles or higher target strengths, take a moment to calculate both the nicotine concentration and finished volume before you start pouring. It prevents one of the most common mistakes with shortfills: adding more nicotine without accounting for the extra liquid that comes with it.

Once you've worked out the amount you need, choose a nic shot that suits the VG/PG ratio and nicotine experience you're looking for, add it to your shortfill and mix thoroughly.

Explore nicotine shots and shortfill e-liquids at UK Vape Supply, with options for both pod-friendly 50/50 liquids and higher-VG shortfills. If you're still deciding which type of vape juice is right for your setup, our VG/PG guide and Nic Salts, Freebase or Shortfills guide are good places to start.