How to Calculate Fabric Consumption

Why consumption is the number behind your price

When a factory quotes a knit garment, the calculation underneath is simple: fabric consumption in kilograms multiplied by fabric price per kilogram, plus trims, plus sewing cost, plus decoration, plus overhead and margin. For a basic tee, fabric alone is often half to two thirds of the ex-factory price. That means a design change that adds 100 grams of consumption moves your price more than most negotiation ever will.

Knit fabrics are bought by weight, so consumption for tees, hoodies and joggers is expressed in kilograms per garment. Woven fabrics are bought by the metre, so shirts and trousers are quoted in metres per garment. The logic below covers both, but the examples focus on knits since that is what most startup brands produce.

The basic formula for knit garments

For a knit garment, consumption is driven by the area of the pattern pieces and the weight of the fabric. A workable estimation formula for a tee is: body length plus sleeve length plus a few centimetres of seam and hem allowance, multiplied by chest width plus allowance, doubled for front and back, then multiplied by the GSM and divided by ten million to convert square centimetre grams into kilograms.

A concrete example, clearly a simplified illustration: a size L tee with 74 cm body length, 56 cm chest width and 22 cm sleeves in 180 GSM cotton jersey. Body panels: 78 x 60 x 2 = 9,360 sq cm. Sleeves roughly 26 x 44 = 1,144 sq cm for the pair, plus neck rib and bindings around 400 sq cm. Total near 10,900 sq cm, which at 180 GSM gives about 0.196 kg of pure pattern area. Real consumption comes out well above this once cutting waste is added, which is the next section, and factories quote the all-in figure, typically around 0.45 to 0.55 kg for a standard-fit tee at this weight once wastage and an average across the size range are included.

The practical takeaway is proportionality: consumption scales linearly with GSM and roughly with the square of size changes. A 240 GSM tee uses about a third more fabric weight than a 180 GSM tee of identical pattern, and an oversized fit with a 64 cm chest can add 15 to 25 percent over a regular fit.

Markers, lays and where the waste comes from

Factories do not cut garments one at a time. They make a marker: a cutting plan that nests the pattern pieces of multiple sizes across the full fabric width, then spread fabric in many layers and cut through the whole lay at once. Marker efficiency, the share of fabric area actually covered by pattern pieces, typically runs 75 to 88 percent for cut-and-sew knits depending on how well the shapes tessellate.

The gap between pattern area and purchased fabric is wastage, and it has several components: the unused spaces between pieces in the marker, edge losses at the selvedges and lay ends, fabric faults that must be cut around, shade splits between rolls, and shrinkage allowance if the fabric relaxes after spreading. Factories usually express all of this as a wastage percentage added on top of marker consumption, commonly 8 to 15 percent for knits, higher for stripes and checks that need pattern matching, and higher again for engineered or placement prints where each panel must land on a specific part of the fabric.

• Marker gaps: 12-25% of the lay depending on pattern shapes
• Selvedge and lay-end losses: typically 2-4%
• Fault cut-outs and shade segregation: variable by fabric quality
• Stripe and check matching: add roughly 5-10% versus solids
• Placement and engineered prints: can add 10-20%

Typical consumption by garment type

The table below gives indicative all-in consumption ranges, including normal wastage, averaged across an adult S to XL size range, for common knit garments. Treat them as planning figures for costing estimates rather than exact commitments; your factory will calculate the real number from your pattern and their marker.

Two patterns in the ranges are worth noticing. First, heavyweight streetwear multiplies consumption fast: an oversized 300 GSM tee can use nearly three times the fabric weight of a 150 GSM promotional tee. Second, small pieces are not free: hoods, kangaroo pockets, cuffs and waistbands add both fabric and sewing operations, which is part of why a hoodie costs multiples of a tee.

How to use consumption when negotiating price

Once you can estimate consumption, factory quotes become legible. If jersey costs, say, 6 to 8 dollars per kilogram and your tee consumes 0.5 kg, fabric is 3 to 4 dollars, and you can judge whether the rest of the quoted price is reasonable for sewing, trims and margin. When a quote looks high, asking which consumption figure was used is a far more productive question than asking for a discount, because it either reveals an error or teaches you what your design actually costs.

Consumption is also your lever for cost engineering. Shortening a body length by 2 cm across thousands of units, removing a chest pocket, switching a stripe to a solid, or accepting a slightly narrower fit each cut real kilograms. Conversely, be suspicious of a quote that undercuts everyone at the same GSM and fit: the easiest way to hit a magic price is to quietly shave GSM or shrink the pattern, and you will not see it until bulk arrives. Fixing composition, GSM with a tolerance, and the measurement chart in writing closes that door.

Wovens in brief: metres instead of kilograms

For woven garments, consumption is quoted in metres at a stated fabric width, commonly 140 to 150 cm. A men's casual shirt typically consumes around 1.6 to 1.9 metres, chino trousers around 1.3 to 1.5 metres, and an overshirt 1.8 to 2.2 metres, all including normal wastage. The same drivers apply: bigger patterns, pattern matching and placement details push metres up, and marker efficiency pushes them down.

Width matters in wovens in a way buyers sometimes miss: the same shirt marker on 150 cm fabric uses fewer running metres than on 140 cm fabric, so when comparing fabric prices per metre, always compare at the same width or convert to price per square metre.