Two luxury vinyl planks sit side by side. One says 20 mil. The other says 5 mm. A reasonable person assumes the 5 mm plank is the tougher one, because five is bigger than nothing and millimeters sound substantial. That assumption is wrong, and it is wrong in a way that costs people money on both sides, either overpaying for a spec they do not need or underbuying for a room that will chew through it.
The two numbers are not competing measurements of the same thing. They describe different parts of the plank, and you need to read both separately to understand what you are actually buying.
A Mil Is One Thousandth of an Inch
Mil is a unit of thickness equal to one thousandth of an inch. It is not an abbreviation for millimeter, despite looking exactly like one. A 20 mil wear layer is 0.020 inches thick, which works out to roughly half a millimeter. Written that way it sounds like almost nothing, and physically it is very thin.
That thinness is not a flaw, because the wear layer is a clear protective film rather than a structural component. Its entire job is to sit above the printed design layer and absorb the daily abrasion that would otherwise wear through to the image underneath. A half millimeter of clear, hard wearing material is doing a surprising amount of work, but it explains why the difference between 12 mil and 20 mil matters even though both numbers sound small.
The Millimeter Figure Measures Something Else Entirely
When a plank is described as 5 mm or 6 mm, that is the total thickness of the plank, usually including the rigid core and sometimes an attached underlayment pad. It tells you about the structure of the plank, how it feels underfoot, how well it bridges small subfloor imperfections, and in part how it resists denting.
Crucially, a thicker plank does not automatically come with a thicker wear layer. The two specs vary independently, and there are 6 mm planks with a 12 mil wear layer sitting next to 4 mm planks with 20 mil. If you only look at overall thickness, you can easily end up with a substantial feeling plank whose protective surface wears through faster than a thinner one would have.
Wear Layer Protects Against Abrasion, Not Dents
This is the distinction that clears up most of the remaining confusion. Wear layer thickness governs resistance to gradual surface abrasion, the kind that comes from grit tracked in on shoes, chairs sliding, vacuuming, and years of foot traffic. A thicker wear layer means more material between the world and the printed image, so the floor keeps its appearance longer.
Denting is a different failure mode with a different cause. A dropped pan or a heavy furniture leg pushes into the plank, and what resists that is core density and how flat and solid the subfloor underneath is, not the clear film on top. A 20 mil wear layer will not stop a dent, and a manufacturer is not overpromising when it declines to claim otherwise.
What each spec is actually telling you:
Mil, usually 6 to 30, measures only the clear wear layer above the design
Millimeters measure the whole plank, core and any attached pad included
Higher mil generally tracks with longer manufacturer warranty terms
Neither number describes waterproof performance, which is a separate property of the core
How to Use Both Numbers Together
Read them as two separate questions. The mil figure answers how long the floor will keep looking the way it looks now under your household's traffic. The millimeter figure answers how the floor will feel, how it handles a subfloor that is not perfectly flat, and how it holds up to impact.
A quiet guest bedroom and a hallway with three kids and two dogs running through it genuinely have different answers, and there is nothing wrong with specifying differently by room rather than buying one product for the entire house. That room by room approach is usually a better use of budget than defaulting to the highest spec everywhere.
Flooring Express goes through both specs with homeowners across Pembroke Pines, Weston, Southwest Ranches, Plantation, Davie, Cooper City, and Fort Lauderdale so the comparison happens on the right numbers rather than on whichever one is printed larger.
Ready to Compare Specs Properly
Flooring Express operates out of Cooper City, FL and serves homeowners throughout Pembroke Pines, Dania Beach, Southwest Ranches, Plantation, Davie, Cooper City, and Fort Lauderdale. If you are comparing luxury vinyl flooring and want help reading what the numbers actually mean for your home, our team can walk you through it.
Contact us to schedule a free in home estimate.
