How much fabric do I need: consumption and yield

What you will learn

Learn to calculate how much fabric a garment takes — with a marker or by estimating from area — and to use yield to know how many meters of fabric to buy for a production order.

Before you start

No special software is needed: the pattern (on paper, PDF or DXF) is enough and, if you already have a marker made, its length. If you work with a textile CAD (Optitex, Audaces, Gerber, Lectra) the calculation is faster, but the formulas in this lesson work just as well by hand.

Concept

Fabric consumption is the amount of fabric a single garment needs, and it can be worked out in two ways: with a real marker (the exact method) or by estimating from the area of the pattern pieces, for a quick quote without making a marker. The result is expressed in linear meters or in kilograms, depending on how the fabric is bought. Yield is the same information seen the other way around and designed for buying: instead of how much fabric one garment takes, it tells you how many garments come out of one meter of fabric. It lets you go straight from a production order to the meters you need to buy, always adding an allowance for flaws, splices and roll ends.

Lesson content

The exact method: marker length divided by garments

The exact way to know how much fabric a garment consumes is to make its marker: lay out all the pieces of the size run over the real width of the fabric and measure the length they take up. Consumption comes from dividing that length by the number of garments that fit in the marker.

For example, a 7.20 m marker containing 6 t-shirts (mixing sizes S, M, L and XL) gives a consumption of 7.20 ÷ 6 = 1.20 m per t-shirt, at that fabric width. That result is the average of the whole size run — the number to use for costing — and not that of a single size.

The figure is valid only for the width the marker was made at: a marker made at 1.50 m is no good for a 1.40 m roll. You have to make the marker again, and consumption rises by more than the width difference, because the nesting of the pieces also changes.

Without a marker: estimating by area and efficiency

When there is no marker yet — for example, to put together a quick quote — you can estimate consumption by adding up the area of all the pattern pieces (in CAD the software calculates it; by hand, you approximate each piece as a rectangle) and dividing it by the fabric's usable width and by an indicative marker efficiency, which usually runs from 70 to 90% depending on the garment.

Example: an adult jogger whose pieces add up to 1.60 m², on a roll with 1.60 m of usable width and 85% efficiency: 1.60 ÷ (1.60 × 0.85) = 1.18 m per garment. If the fabric has a nap or stripes have to be matched, efficiency drops to 75-80% and consumption rises to 1.25-1.33 m.

Yield: the same calculation, seen the other way around

Yield is how many garments come out of one meter of fabric, for a given width, pattern and marker. It is unit consumption inverted, and it is more direct when the question is not 'how much fabric does one garment take' but 'how much fabric do I have to buy for an order'.

The formula for going from an order to the meters needed is: meters of fabric = number of garments ÷ yield. For example, if a marker gives 24 garments in 3 meters, the yield is 24 ÷ 3 = 8 garments per meter; for an order of 120 garments, the meters needed are 120 ÷ 8 = 15 meters.

The allowance and converting meters to kilograms

Both the consumption per garment and the meters given by the yield formula are usable fabric, the fabric that actually becomes garments. To that number you must always add an allowance for fabric flaws, splices between rolls and end losses in the lay, which generally runs from 3 to 8% on top of the fabric purchased.

Knit fabrics (jersey, fleece, rib knit) are often sold by the kilogram and wovens (gabardine, denim, poplin) by the meter. To convert from meters to kilograms: kilograms = linear meters × width in meters × fabric weight in g/m², divided by 1,000. A t-shirt that consumes 0.75 m of jersey 1.80 m wide and 150 g/m² weighs 0.75 × 1.80 × 150 ÷ 1,000 = 0.202 kg (202 g).

Practical example

A 7.20 m marker with 6 t-shirts gives a consumption of 1.20 m per t-shirt. To quote an order of 300 t-shirts of the same style and the same fabric, the most direct way is to multiply: 300 × 1.20 = 360 m. Thought of as yield it comes out the same: the yield of that marker is 6 ÷ 7.20 ≈ 0.83 garments per meter, and 300 ÷ 0.83 also gives 360 m — before adding the allowance.

Common mistakes

Costing with the consumption of size M and applying it to the whole size range.: Use the average consumption of a multi-size marker: each adult size usually adds between 3 and 5% more fabric than the previous one, so a 4XL consumes quite a bit more than an XS.

Using a consumption or yield calculated at one fabric width to buy at another width.: Make the marker again for each roll width: the same marker gives a different consumption and yield at 1.50, 1.60 or 1.80 m.

Buying exactly the meters the formula gives, without adding an allowance.: Add between 3 and 8% allowance for flaws, splices and roll ends before closing the purchase.

Modeltex tip

Modeltex patterns come with the complete size range (XS to 4XL in adults, 2 to 18 in kids). If you work in DXF/AAMA or PDS you can nest them in your own CAD and get the real consumption and yield at your fabric width; if you do not have CAD, Modeltex builds the MRK marker optimized for your fabric so that consumption comes from a real marker and not from an estimate.

Exercise

Pick a pattern of your own (it can be a simple garment, such as a t-shirt). If you already have a marker, note its length and the number of garments it contains; if not, add up the approximate area of its pieces. Calculate the consumption per garment with the appropriate formula, then calculate the yield (1 ÷ consumption) and use it to estimate how many meters you would need for an order of 100 garments, adding a 5% allowance.

Frequently asked questions

How is a garment's fabric consumption calculated?

By making a marker with all the pattern pieces over the fabric's usable width and dividing the marker length by the number of garments it contains. Without a marker, it is estimated by dividing the area of the pieces by the usable width and by an indicative efficiency of 70 to 90%, and adding a 3 to 8% allowance.

What is fabric yield and how does it differ from consumption?

Yield is how many garments come out of one meter of fabric; consumption is how much fabric one garment takes. They are the same relationship inverted: yield = 1 ÷ consumption, and consumption = 1 ÷ yield.

How do I calculate how much fabric to buy for a production order?

Divide the number of garments in the order by the yield: meters needed = number of garments ÷ yield. For example, with a yield of 8 garments per meter, an order of 120 garments needs 120 ÷ 8 = 15 meters, before adding the allowance.

How do I convert consumption from meters to kilograms?

Multiply the linear meters by the fabric width in meters and by the fabric weight in g/m², and divide by 1,000. For example, 0.75 m × 1.80 m × 150 g/m² ÷ 1,000 = 202 g.

How much allowance should I add to consumption or yield?

Generally between 3 and 8% on top of the fabric purchased, for roll flaws, splices between batches, end losses in the lay and cutting samples. It is worth adjusting the percentage to what you measure with each supplier.

Are consumption and yield the same for all sizes?

No. Each adult size usually adds between 3 and 5% more fabric than the previous one, and yield changes with the fabric width and with the size mix of the order. It is best to take it from a multi-size marker with the real size ratio and to make the marker again if the roll width changes.

Summary

Fabric consumption per garment comes from dividing the length of a marker by the number of garments it contains, or is estimated from the area of the pieces divided by the usable width and the marker efficiency. Yield is that same information inverted (garments per meter) and is used to calculate directly how much fabric to buy for an order: meters needed = number of garments ÷ yield. To either calculation you must always add a 3 to 8% allowance before closing the purchase.

Go back to the full course or ask the Modeltex Lab AI.