Justfog Q16 coils, 1.2 or 1.6 ohm by voltage step
The Q16 has kept the same name since 2015, and that continuity is exactly what muddles the spare-parts shelf. Justfog Q16 coils now come as a 1.6 ohm, a 1.2 ohm and a part labelled FF, for four devices with almost identical names. On the Pro Plus nothing is set in watts. The battery steps through four voltages, and the coil you fit decides how much power each step actually delivers.
Which Justfog Q16 coils to pick, 1.6 or 1.2 ohm
The 1.6 ohm is the baseline value of the series. Justfog ships it in the Q16 Pro Plus kit, described as a cotton coil, and it gives the tightest draw for mouth-to-lung vaping. The 1.2 ohm, which the manufacturer lists as compatible with the same tank, runs warmer at the same voltage and opens the vapour up a little without leaving mouth-to-lung territory.
Choosing between Justfog Q16 coils therefore comes down to heat. For a thin liquid high in propylene glycol and a narrow draw, the 1.6 ohm remains the reference. For warmer, denser vapour the 1.2 ohm takes over, at the cost of a battery that drains sooner.
Four voltage steps, two real wattages
The Q16 Pro Plus has no watt-by-watt adjustment. A button cycles through four voltages, and the power delivered depends on the coil fitted. The table follows the chart Justfog publishes on the Pro Plus product page.
| Step | With 1.2 ohm | With 1.6 ohm |
|---|---|---|
| 3.5 V | 10 W | 8 W |
| 3.8 V | 12 W | 9 W |
| 4.1 V | 14 W | 11 W |
| 4.4 V | 16 W | 12 W |
The figures check out with Ohm’s law, power equals voltage squared divided by resistance. At 4.4 V a 1.2 ohm coil receives about 16.1 W and draws close to 3.7 A, while a 1.6 ohm on the first step takes 7.7 W, rounded to 8 on the chart.
What the chart means for your setting
The same step does not produce the same vapour from one coil to the other. Swapping a 1.6 for a 1.2 ohm while staying on 4.1 V lifts the power from 11 to 14 W, three watts more without touching the button.
The sensible move after a change of value is to drop one step, then climb back if the flavour feels thin. A fresh 1.2 ohm started straight on 4.4 V takes its 16 W before the cotton has finished soaking.
The Q16 FF plays by other rules
The 2022 Q16 FF works differently. Its spec sheet lists constant wattage on three levels, 9, 11 and 13 W, for a 1.2 ohm coil described as a vertical coil. Here the battery adjusts the voltage itself to hold the chosen wattage, and the 1.6 ohm does not appear in its documentation at all.
The FF 1.2, a newer generation of Justfog Q16 coils
In 2025 Justfog added a part called the FF 1.2 Coil, FF standing for Flavor Focused. The manufacturer presents it as developed to get the most out of the Q16 series, with the pitch centred on stronger flavour rather than the easy-going reliability of its standard coils.
A clear specification
The FF 1.2 is rated at 1.2 ohm, uses iron-chrome-aluminium wire, measures 9 mm across and 17 mm tall and weighs 2.1 g. Its recommended range runs from 10 to 16 W, which matches the four steps of a Q16 Pro Plus fitted with a 1.2 ohm exactly. The manufacturer’s artwork shows it screwed onto the bottom cap of the Pro Plus tank.
Two parts, one label
The FF name therefore covers two different things. The vertical coil supplied with the Q16 FF in 2022 and the 2025 FF 1.2 Coil share the badge, yet Justfog publishes no interchangeability chart between them. Before ordering for a Q16 FF, compare the shape of the original part with the pack photo rather than trusting the two letters.
Q16, Pro, Pro Plus and FF, what the spec sheets say
Justfog dates the four devices itself, the Q16 in 2015, the Q16 Pro in 2019, the Q16 FF in 2022 and the Q16 Pro Plus in 2024. The Pro Plus takes its coils through the bottom cap of the tank, a design whose longevity the manufacturer likes to stress, while the FF follows its own logic.
The global Q16 Pro Plus lists a 3 ml tank, compatible with 1.6 and 1.2 ohm, on a 1,500 mAh battery charged over USB-C. In the UK, refillable tanks are capped at 2 ml, so only a version of 2 ml or less can be sold here. The Q16 FF lists 1.9 ml and a 900 mAh battery, already under that ceiling.
The voltage chart above is published for the Pro Plus. For the original Q16 and the Q16 Pro, coil compatibility is best checked on the device’s own spec sheet and on each pack before ordering.
Fitting and priming the coil
The Pro Plus leaflet comes down to three moves. Unscrew the base of the tank, screw the new coil onto that bottom cap, then screw the assembly firmly back onto the tube. The same bottom-fitted logic appears in our Voopoo Drag X coil change walkthrough, with comparable priming precautions.
Justfog then asks you to fill the tank to 80 per cent at most and wait five minutes before the first puff, so the liquid can soak right through the cotton. Firing a dry coil damages it straight away, and the manufacturer advises topping up before the tank runs empty.
One last instruction from the leaflet, never block the airflow completely to force a stronger draw. The manufacturer warns that the resulting suction causes leaks and overheating, two faults that are often wrongly blamed on a faulty coil.
FAQ
Questions that come up when ordering a pack, alongside values and voltage steps.
How long does a Justfog Q16 coil last?
The manufacturer gives no figure, it only praises the longevity of its bottom-fitted coils. On a stepped device the best clue is the step itself. Once you need to go up a notch to get the original vapour back, the wick is clogging and a replacement is near.
Can a 1.2 ohm coil go on a Q16 Pro Plus?
Yes, with no special setting, since the manufacturer’s chart covers all four steps for both values. On the top step the 1.2 ohm receives 16 W, the upper limit of the FF 1.2 range.
Which liquid suits a 1.6 ohm coil?
Justfog presents the Q16 series as a mouth-to-lung device, and the 1.6 ohm pairs well with thin liquids high in propylene glycol. In the UK, nicotine-containing e-liquid is capped at 20 mg/ml and sold in bottles of no more than 10 ml. A very high vegetable glycerine liquid soaks into this tight cotton more slowly.
Does a 1.2 ohm coil really drain the battery faster?
Yes, and the sum shows by how much. On the 4.4 V step the 1.2 ohm draws about 3.7 A against 2.75 A for the 1.6 ohm, a third more current on every puff. On the 1,500 mAh battery of the Pro Plus, that means fewer puffs between charges on the same step.
Do nicotine salts suit Justfog Q16 coils?
Yes. A 1.2 or 1.6 ohm coil run between 8 and 16 W sits in tight-draw territory, which is what nicotine salts are designed for. A low-strength salt is usually enough at that power.
Justfog Q16 coils, voltage before value
On a Q16 the value never tells the whole story. A 1.6 and a 1.2 ohm on the same step have little in common, and the 2025 FF 1.2 is not the vertical coil of the Q16 FF despite the shared badge.
Reading the voltage chart before ordering is the surest way to match Justfog Q16 coils to your device. The same habit applies to our Zeus coils breakdown, to the Geekvape series and to any technical consumable, whatever the brand.
Editorial content for adult readers only. Nicotine is a highly addictive substance, and vaping products are not for sale to anyone under 18 in the UK. This article is not a buying recommendation.
