Sub-Ohm Vaping: The Basics

Posted by Vaporizer Chief on 7th Jun 2021

Ohms law refers to the current of an electronic device, in this case the atomizer. Ohm’s law divides the voltage difference by the current. This comes into play when trying to create a thicker and more intense vapor while utilizing a lower resistance atomizer. You will get a more warm, throaty vapor with a lower Ohm. You will also notice that your battery and eJuice run out a bit more.

What is Sub-Ohm Vaping?

Before explaining what sub-ohm vaping means exactly, it's important to discuss what an ohm is. An ohm is a standard unit of measurement for determining the resistance or capacity of an object (in this case your vape's coils) to conduct current.

Sub-ohm vaping means vaping on a coil build with a measured resistance of anything lower than 1 ohm. Vaping at sub-ohm levels display a reading of anywhere between 0.01 to 0.99 ohms.

The Basics

When the technology in vaping was in its infancy, all pen-type vapes had resistance higher than 1 ohm. This was due to limitations in battery technology. The innovative technology was lacking in atomizers and coils which could handle higher amounts of current.

sub ohm voltage chart

sub ohm voltage chart

Since then, vaping has become more popular. That has resulted into a lot more research and development has poured into this side of the world. This let vaping evolve to the point where sub-ohm vaping has pretty much become the norm for most vapers. It's still important to note that this doesn't mean one is better than the other. Yet, it boils down to personal preference which we'll talk about down below.

Why Vape Below Zero or Sub-Ohm?

The draw is a heavier and the produced vapor is thicker than usual. Sub-Ohm vapers generally take hits straight to their lungs allowing them to draw the large amount of vapor emitted from their negative Ohm atomizer tanks. In general, Sub-Ohm vaping works best with more vegetable glycerin than propylene glycol because it leads to a less throat burning draw. Additionally they also use less nicotine in Sub-Ohm mods because you’re getting more.

Sub-ohm Vaping VS Regular Vaping

One of the key selling points of sub-ohm vapes is the fact that it lets you pump large amounts of watts into your vape. The result is a lot more battery power and e-liquid used up. What you get out of it in return is a warmer, denser, more intense, and flavorful vapor.

Ohm-vaping doesn't use up your batteries as much thanks to the lower current from the coils. This leads to a cooler and more relaxed vaping experience compared to below ohm vaping. Ohm vaping also uses less e-liquid. Depending on your setup, the flavor might be a bit less than sub-ohm vaping, but that isn't true in all cases.

3 Factors of Sub Ohm Vaping

Coil resistance

Coil resistance plays one of the most important if not largest roles when it comes to producing a true sub-ohm vape. It's important to note, there are lots of different materials used to build coils nowadays. Coil building materials include kanthal, stainless steel, nichrome, nickel, and titanium. Now listen up because this is the important bit. Each one of these metals has their own resistance value. It's important to know if you're specific about the exact resistance of your coils.

The thickness or gauge of the coiled wire, as well as its length play a big part in determining the resistance of a coil. To give you a rough idea, thicker/lower gauged wires have a much lower resistance compared to thinner/higher gauged ones. When it comes to coil length, using a longer wire to produce a longer coil or a coil with more “wraps” will lead to a coil with higher resistance. This is because there's more metal that the current needs to flow through)

Shorter wires or coils with less “wraps” have a much lower resistance or ohm value. This is because the current isn't impeded by that much metal as compared to a longer coil. If you're building a coil with the highest possible resistance as an example, (not recommended) you'd be using the thinnest wire possible with at least 8-10 wraps to build the coil.

Battery voltage

Taking note of the voltage your batteries are capable of delivering is important. This dictates how much current can flow out of it into your coils. Most batteries for vaping deliver a constant 4.2 volts when used with the voltage tapering down as the battery nears the end of its discharge cycle.

When regulated mods weren't a thing and mechanical mods reigned supreme, there was no way for vapers to adjust the voltage by the batteries. The workaround was to lower the resistance of the coil so that the same 4.2 volts would be capable of delivering a lot more current or amps to the coil. This is generally how sub-ohm vaping became popular.


With the advent of more advanced and reliable regulated mods, it's now possible to boost the voltage supplied by the batteries. You can deliver more wattage or current to your coils regardless of their resistance. You're not constrained to building low resistance coils for an intense vaping experience.

It's still important to note that each coil depending on its resistance and how it's built can only take a specific number of watts. After this, the coil gets too hot. It will start burning your e-liquid as well as the wicking material. Low resistance or sub-ohm coils are still preferred in this regard. They can spread heat more and thus letting you deliver a higher number of watts before the coil gets too hot to vape.

ohms law - voltage/resistance = electrical current


Sub-ohm vapes are more flavorful and produce more vapor compared to high resistance vapes. Higher heat mass from the thicker wires allow the coils to vaporize a lot more e-liquid. This is why you get a big increase in flavor and vapor production.


The boost in flavor production means that vapers are able to appreciate the subtle nuances of flavor in their e-liquids. While more vapor production isn't what every vaper out there wants from their vape, current trends do show that most vapers do get a better kick out of their vape when more vapors produced.

Another advantage is that the higher amount of e-liquid consumed per puff means you can vape with lower nicotine. While nicotine has always been a popular component of e-liquids, it can sometimes get in the way of producing a flavorful experience. and This is something that below-ohm vaping can bypass. Sub-ohm vaping can produce a much warmer vape which is also desirable by some vapers.


While popular, sub-ohm vaping has its own share of drawbacks. The first is it might not be the most ideal setup for a beginner. The increased amount of vapor and nicotine can sometimes be overwhelming for most beginners. Another con is that sub-ohm vaping consumes a lot more e-liquid. It's definitely more expensive than vaping with higher resistance coils.

Thanks to the higher heat and e-liquid vaporized, the coils used for sub-ohm vaping have a tendency to burn out or gunk up faster. The need to replace the coils can be a hassle for those who would rather not spend the time and the costs.

ohm - lower resistance - higher resistance

Sub Ohm Tanks

Sub-ohm tanks function like any other tank. There is a reservoir of e-liquid that feeds into the wicks. This keeps your wicks and coils juiced up and ready for vaping. The difference lies within the coils used in the tank. The lower resistance coils used in sub-ohm tanks leads to a higher rate of e-liquid consumption.

Depending on their design, not all tanks are able to keep up with the rate of vaporization when it comes to wicking. Chain vaping for a long period of time might not be possible. You can end up with nasty dry hits (burning the coil without any e-liquid in it)

Is sub-ohm vaping dangerous?

The first thing to be clear about is that sub-ohm vaping can be dangerous if you aren’t paying attention to your battery. As you drop lower in Ohms following Ohms and Joules Law of electricity, the battery will increase power output. It is imperative that you don’t exceed the amperage limit of your battery or it could lead to explosion or fire. Sub-ohm vaping definitely has its inherent risks, especially where high capacity batteries and large amounts of heat are involved. The good news is that most of these risks can be avoided by using a regulated mod. When mechanical mods were still the most dominant type of device in the market and sub-ohm vaping/low resistance coils were the trend, many vapers would often use batteries that didn't have the capacity of discharging current at the required rate. This often leads to the vape battery venting or exploding.

An internal chip built into a regulated mod controls the discharge rate of the battery. It ensures that the output of its current isn't beyond its capabilities. This creates a much safer vaping experience. Despite these advancements, it’s always advisable to take precautions to further lower the risk of sub-ohm vaping.

  • Always use original and high quality batteries sourced from legitimate vendors or suppliers.
  • Never use damaged or worn batteries.
  • Don't let your vape get too hot as the heat generated by the coil tends to cause the temperature of your device (including the batteries) to shoot up. It creates an unfavorable situation when it comes to battery safety.

What Do I Need to Start?

As far as a mod for Sub-Ohm vaporizing you should get a higher powered battery than you would with a 1 Ohm piece. A lot of vapers prefer to use a variable voltage or wattage battery. Get yourself a IMR or hybrid lithium batteries from a reputable brand. Avoid getting Li-Ion, Lipo or ICR battery types to decrease the risk of spontaneous battery explosions.

Voltage drop is also key in this style of ecig vaping, you want yours to be quite low. Voltage drop is the amount of voltage lost when the battery sends a current through your mod to your coil. You need a low voltage drop for adequate Sub-Ohm vaping. Avoid multiple piece tubes, telescoping tubes, threaded contacts or spring loaded. Those styles have a higher voltage drop. Atomizers that have the lowest voltage drop are single piece tube, fixed position contacts and magnetic switch.

How Do I Care for My Sub-Ohm Mod?

It is important to keep your mod quite clean. Clean all threads, vents, switch and contacts thoroughly and as often as possible. If your switch is spring loaded take note frequently on how worn out the spring has gotten. However if possible try not to use spring loaded at all because it will wear out quickly and/or fail.

Sub-Ohm vaping will definitely drain your battery more quickly, keep some extra batteries around to avoid having to charge in your car or have no eCig at all. Never, ever expose your battery to extreme temperatures or water, if you do so stop using the device immediately.