Vape coil guide: ohms, wattage and coil life
Everything happens on a component a few millimetres across. A vape coil heats, clogs, wears out, and on its own decides how dense the vapour feels and how faithfully the flavour comes through. Yet the number stamped on its side stays a mystery to most people who buy one. What does 0.4 ohm or 1.2 ohm actually mean, and why does that single figure dictate the rest of the setup? Here is the component the lab considers the most consequential in any British tank or pod.
What a vape coil actually does
A vape coil is the heating element that sits between the battery and the e-liquid, inside a tank or a pod. It is made of a resistive wire, or a perforated metal strip called mesh, wrapped around or laid against a cotton wick.
When the cell sends current through it, the metal rises in temperature and turns the liquid held in the cotton into vapour. So the coil produces the vapour, carries the flavour, and sets the sensation in the mouth. Nothing else in the device has that much influence over the result.
The figure engraved on the body, expressed in ohms, measures how strongly the element opposes the passage of current. The lower that value, the more current flows, and the harder and faster the element heats. That relationship is why the same device cannot be set the same way for every coil you screw into it.
Reading the ohm rating on the coil
The ohm rating is not decoration. It determines the style of draw the coil was designed for, the amount of power it expects, and the volume of vapour it will make. British listings split the market at roughly 1.0 ohm.
Above 1.0 ohm, the element heats moderately and suits mouth to lung vaping, usually shortened to MTL. The draw is tight, the vapour discreet, and liquid consumption stays low. This is where higher nicotine strengths normally sit, since the vapour volume is small and each puff delivers less of it.
Below 1.0 ohm, you are into sub ohm territory. Far more current passes, the element runs hot, and the coil expects a good deal more power from the device. The result is dense vapour, an airy draw and a generous aromatic output, normally paired with direct to lung vaping, or DTL, and with low nicotine strengths.
Between those two poles sits the category British shops sell more of than any other: restricted direct lung, or RDL. It is a lung inhale through a deliberately narrowed airflow, and the coils built for it cluster around the 1.0 ohm mark on either side. Anyone unsure where their kit falls will find the practical differences set out in our guide to sub ohm tanks, power and draw.
Mesh and wire builds
For years the coil meant wire wound into a spiral. Mesh has largely displaced it in the tanks and pods sold across the UK, and the change is worth understanding rather than treating as marketing.
Mesh is a thin perforated metal strip. It presents a much larger and more even heating surface than a wound wire of the same rating, so it comes up to temperature faster and heats the wick more uniformly. Flavour tends to read more cleanly from the very first puffs.
That geometry explains why recent tanks and pods almost all ship with mesh as standard. On the bench, a well wicked mesh strip gives a steady output where an older wound coil could vary noticeably from one puff to the next. Wound wire has not disappeared, but it now sits mainly in MTL coils and in rebuildable atomisers.
Wire materials and what they change
The metal itself matters as much as the shape. Kanthal remains the historical reference: stable, undemanding, and intended for straightforward wattage mode. It is what most standard coils use.
Stainless steel is the versatile option, because it works in wattage mode and in temperature control. Nickel and titanium exist almost exclusively for temperature control, a mode that limits runaway heating on devices that support it, and they should never be run in plain wattage mode. In practice, the material is dictated by the device you own rather than by taste.
Power: read the range printed on the vape coil
Every coil carries a wattage range, either laser etched on the body or printed on the packaging. That range comes from the manufacturer who designed the wick, the metal and the airflow together, and it is the only figure you should treat as authoritative.
The lab does not publish power settings of its own. Lower resistance draws more current from the cell, and the cell has its own continuous discharge limit set out in the manufacturer’s datasheet. Both documents, the coil marking and the cell datasheet, take precedence over any general advice. If you want to see how ratings and power bands line up across the market, our wattage chart by ohm rating sets them out coil by coil.
The symptoms of getting it wrong are easy to recognise. Too little power and the wick stays flooded, the liquid moves poorly and the vapour comes through lukewarm. Too much and the cotton dries faster than the liquid can replace it, which gives the harsh burnt taste every vaper knows.
Why UK rules shape the coil market
British hardware is fixed small by law. Under the Tobacco and Related Products Regulations 2016, every tank and pod sold legally in the UK is capped at 2 ml, and nicotine containing e-liquid is capped at 20 mg/ml in 10 ml bottles.
That has a direct consequence at the bench. Because the hardware cannot grow, British vapers change coils rather than changing tanks, and the coil becomes the main variable in the setup. A 2 ml tank also empties quickly, which means more refills, more chances to run it low, and a harder working element.
It also explains the pairing you see in every British shop. High strength nicotine sits on MTL coils above 1.0 ohm, where the vapour volume is modest, while sub ohm coils are sold alongside low strength liquid because they vaporise far more per puff.
How long a vape coil lasts
British retailers commonly quote one to two weeks for a coil, and that figure is realistic for a 2 ml tank in daily use. It is a range, not a schedule, because it depends on how much you vape, at what power, and on what liquid.
Sweetened liquids are the main accelerator. Sucralose and similar sweeteners caramelise on the metal and leave a dark residue that no amount of running will clear. Dark liquids, high power and frequent low tank puffs all shorten the same window. The signs of a spent element, and how to tell them from a wicking fault, are covered in our piece on how long a coil lasts before it needs replacing.
Priming and everyday care
A new element must be primed before its first use. Put a few drops of liquid directly onto the exposed cotton, fit it, fill the tank and leave it standing for several minutes. Skipping that step is the single most common reason a coil is ruined within minutes of being fitted.
Day to day, avoid vaping on a nearly empty tank, stay inside the range marked on the element, and take a couple of gentle draws with no power before the first proper puff. Our note on priming a coil correctly works through the sequence in detail.
No routine makes a coil permanent. The cotton eventually saturates with residue and the metal keeps its deposits, and at that point replacement is the only option.
Frequently asked questions
How do I know which coils fit my tank?
Compatibility depends on the tank or pod model, not on the brand of your battery. Each tank accepts one specific coil series, usually identified by a short reference code. Check the tank instructions, or read the marking on the coil that came fitted.
Does a lower ohm rating use more e-liquid?
Yes. A low rating heats harder, makes more vapour and therefore consumes more liquid per puff. With a 2 ml tank, a sub ohm setup empties a 10 ml bottle noticeably faster than an MTL one at the same frequency of use.
Can a coil be cleaned and reused?
The cotton and metal in a factory coil do not really recover. Rinsing removes some residue and can buy a little time, but it restores neither the flavour nor the original heating behaviour. Rebuildable atomisers are the exception, since the cotton is replaced by hand.
Why does my brand new coil taste burnt straight away?
Almost always because priming was rushed. Cotton that has not fully absorbed liquid heats dry on the first puffs and degrades immediately. Wetting the wick, filling the tank and waiting a few minutes prevents it.
Do I need a specific device for sub ohm coils?
A sub ohm coil asks for a device able to supply the power the coil is marked for, and a cell in good condition. Small pod batteries often cannot. Check that the range printed on the coil sits within what your device states before fitting it.
Choosing a coil with the numbers in front of you
The ohm rating, the build, the metal and the printed wattage range form one coherent system, and reading them together is what separates a considered purchase from a guess at the shelf. Match the rating to the draw you want, MTL above 1.0 ohm, RDL around it, DTL below, then let the marking on the body set the power.
In a market where the tank is capped at 2 ml and the liquid at 20 mg/ml, the vape coil is the one part of a British setup you genuinely choose and genuinely replace. Understanding that small engraved figure is what turns a fitted vape coil into a stable, repeatable vape rather than a fortnightly gamble, and it is the component the lab keeps returning to on every atomiser it tests.
Editorial content for adult readers only. Not intended for anyone under 18 in the United Kingdom. Vaping products normally contain nicotine, a substance that causes addiction. This article is informational and is not a buying recommendation.
