Guide · For the trade
Carpet face weight: what the number means on a spec sheet and what a good one is
Carpet face weight is the weight of the pile fiber alone in one square yard of carpet, in ounces, with the backing excluded; a 40 oz carpet has 40 ounces of yarn standing on each square yard. On its own it does not tell you how a carpet will wear. Divide it by the pile height and you get density and density with fiber and construction is what predicts the floor in year ten. Residential cut piles run 30 to 60 oz; commercial loops do their job at 20 to 32 oz because the pile is short and dense.
This guide is for the designer or junior reading a mill spec sheet and trying to decide whether the face weight is good, whether the client's "I want a 70 oz carpet" makes sense and what to write instead. It covers the definition, face weight against total weight and density, the bands by use, how wool and nylon differ at the same number and the questions that come up in every presentation.
What face weight is and what it is not
Face weight, also called pile weight or yarn weight, is measured in ounces per square yard of finished carpet and counts only the fiber above the primary backing. Total weight adds the primary backing, the latex and the secondary backing and on a tufted carpet it is often 60 to 90 oz when the face weight is 35 to 45 oz. Mills quote whichever reads better, so check the line: a spec sheet in our library from DMI, for example, lists a 30 oz face weight next to an 85 oz total weight for the same wool broadloom. When a sales sheet says "weight" with no qualifier, assume total and ask.
Face weight, pile height and density
The same 40 oz of yarn can be packed into a 1/4-inch loop or stretched into a 3/4-inch plush. The first is dense and will wear like a commercial floor; the second is soft and will show traffic in a season. Density is the number that captures the difference: face weight multiplied by 36, divided by the pile height in inches, in ounces per cubic yard. A 40 oz carpet at 1/4 inch is 5,760; the same yarn at 3/4 inch is 1,920. Residential cut pile for a living room should be 3,000 or more; stairs, halls and anything commercial want 5,000 and up. The carpet density guide works through the calculation; the pile height guide covers the other half of the formula.
What is a good carpet face weight, by use
| Face weight | Typical construction | Where it belongs | Note |
|---|---|---|---|
| Under 25 oz | Commercial level loop, flatweave, printed nylon | Offices, corridors, classrooms | Low pile and high density; the number is small because the pile is short, not because the carpet is light duty |
| 25 to 35 oz | Nylon loop and low cut pile, wool loop | Family rooms, stairs, halls, hospitality guestrooms | The working range for most of a residence; Milliken's nylon broadloom in our library runs 26 to 50 oz with pile heights of 0.30 to 0.375 in |
| 35 to 50 oz | Cut pile, textured and patterned tufted, wool Wilton | Living rooms, bedrooms, dining rooms | The comfortable middle; at 1/2 in pile this is a 2,500 to 3,600 density |
| 50 to 70 oz | Plush, Saxony, dense wool cut pile | Primary bedrooms, media rooms | Feels luxurious; check density, because weight at 3/4 in pile wears faster than 40 oz at 3/8 in |
| Over 70 oz | Shag, high-pile wool, some hand-loomed broadloom | Low-traffic rooms, bound rugs | Weight here is pile length. A hand-loomed wool broadloom can run past 100 oz and is a bedroom product |
Wool and nylon at the same face weight
Wool yarn is bulkier for its weight than nylon because of its crimp, so a 40 oz wool reads fuller than a 40 oz nylon and a wool spec sheet will often show a higher face weight for a product that performs the same. Nylon's resilience comes from the fiber, not the weight; a 28 oz solution-dyed nylon loop outlasts a 50 oz polyester plush in any hallway. Polyester and polypropylene are sold on face weight precisely because it is their best number. When comparing across fibers, compare density and construction first and the face weight last.
How to read face weight on a mill spec sheet
Mills print it in different places. Milliken and Masland list "pile weight" or "face weight" in oz/yd2 with the pile height and gauge beside it. Woven mills such as Bloomsburg and Prestige Mills may give "pile weight" for Wilton and Axminster and a wire height in thousandths of an inch instead of a pile height. European mills give grams per square meter; divide by 33.9 for ounces per square yard. If a sheet has total weight only, ask the rep for the face weight or the density; a mill that cannot supply either is telling you something.
What to write on the spec
Write the construction, the fiber, the face weight in oz/yd2, the pile height in inches and the density, in that order, with the mill style number. "Tufted cut pile, 100 percent nylon type 6,6, 40 oz/yd2 face weight, 0.375 in pile height, 3,840 oz/yd3 density" is a specification; "40 oz carpet" is a wish. For stairs, halls and commercial work add the radiant panel class and the emissions certificate; the how to specify carpet guide has the full list.
Questions designers ask
What does face weight mean?
The ounces of pile yarn in one square yard of carpet, backing excluded. It tells you how much fiber is there, not how tightly it is packed. Pair it with pile height to get density, which is the number that predicts wear.
Is 70 oz carpet good?
It is heavy and in a plush or a Saxony that weight is mostly pile length. At 3/4 inch pile a 70 oz carpet has a density around 3,360, fine for a bedroom and soft underfoot, but no more durable than a 40 oz at 3/8 inch. For a living room or a hall, a 40 to 50 oz carpet at 1/2 inch or less is the better spec.
Can you tell face weight by weighing a sample?
No. A sample weighs face plus backing and a 12 by 12 inch cut is a ninth of a square yard with raw edges, so the arithmetic is unreliable. Take face weight from the mill's spec sheet or test report. What a sample does tell you is density, by bending it over your hand and seeing how much backing shows.
How much carpet does a 10 by 12 foot room take and how is it priced?
Thirteen and a third square yards of floor, which becomes 16 to 18 square yards once the 12 ft roll width and the seam plan are applied. Carpet is quoted to approved trade accounts by the square yard, net, with face weight and construction as the price drivers along with fiber; see the carpet yardage guide for the roll math.
Is face weight or density more important?
Density, every time, with fiber a close second. Face weight is an input to density and a rough guide to softness. Two carpets with the same face weight and different pile heights will wear completely differently.
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