Fabric Consumption Calculator: The Short Answer
A brand plans 1,000 T-shirts with a 70 centimetre body length, a 22 centimetre sleeve and a 52 centimetre flat chest, in a 180 gsm fabric that is 150 centimetres wide. With 4 centimetres of allowance in each direction and 10 per cent for wastage, the fabric consumption calculator gives 0.213 kilograms and 0.79 metres per T-shirt, so the order needs about 213 kilograms, or 788 metres, of fabric. The estimate rests on one formula: garment area from flat measurements, converted to weight with the gsm and to length with the width.
Every figure here is an estimate. Real consumption comes from a cutting marker made for the actual pattern, which factories produce as part of costing. The fabric consumption calculator is for budgeting, for questioning a quote and for comparing designs, not for replacing the marker.
Used well, it saves time at the quoting stage. If a factory states a consumption far from what the calculator gives, that is not proof of an error, since patterns differ, but it is a good reason to ask how the number was reached. A buyer who can reproduce the rough size of the figure is better placed to have a useful conversation about pattern efficiency, size range and fabric choice.
Use the Fabric Consumption Calculator
Enter the finished measurements of the garment: body length, sleeve length and the flat chest width, which is half the chest circumference measured with the garment laid flat. Add small allowances for hems and seams, the fabric weight in gsm, the usable width of the cloth and a wastage percentage. The fabric consumption calculator returns the fabric per piece in kilograms and metres, the garment area and the totals for your order.
Fabric consumption calculator
Kilograms and metres per garment
An estimate, not a marker-based consumption. The allowances and wastage are placeholders; replace them with figures from your pattern and factory.
For a hoodie, use the same measurements and add the area of the hood, pockets and cuffs in the extra panels box. If you do not have those areas, ask your factory for the pattern piece sizes, or treat the result as a lower bound. The calculator is deliberately simple so that every number can be checked, which is the main advantage of a fabric consumption calculator that works from flat measurements.
Take the measurements from a sample or a size chart that you trust. Measure the body length from the high point of the shoulder to the hem, the sleeve from the shoulder seam to the cuff edge and the chest across the garment just below the armhole, with the garment laid flat and smoothed. Consistent measuring habits matter more than precision to the last millimetre, because the allowances and the wastage already absorb small differences.
How the Fabric Consumption Formula Works
The formula treats the garment as two rectangles, a front and a back, each as long as the body plus the sleeve, plus an allowance, and as wide as the flat chest, plus an allowance. Doubling the rectangle covers both panels. The area multiplied by the fabric weight gives the weight of cloth, and dividing the area by the fabric width gives its length.
From measurements to fabric
- 1Add the lengthsBody length + sleeve length + length allowance.
- 2Add the widthFlat chest width + width allowance.
- 3Find the areaLength × width × 2 panels, plus any extra panels, in cm².
- 4Add wastageMultiply by 1 + wastage ÷ 100.
- 5Convert to weightArea in m² × gsm ÷ 1,000 = kg.
- 6Convert to lengthArea in m² ÷ width in m = metres.
One consequence of the formula is that consumption scales with the product of length and width, so a small increase in both has a larger effect than either alone. Growing a body by 2 centimetres in length and 2 in width adds about 5.7 per cent to the area for the example T-shirt. When you grade a size range, consumption therefore climbs faster at the large end, which is why quotes are usually based on a medium size and adjusted for the spread of sizes in the order.
Because the sleeve length is added to the body length, the formula is a rule of thumb for knit tees and sweatshirts with set-in or raglan sleeves. It is less reliable for shaped woven garments, where pattern layout matters more. Standards bodies such as the ISO and ASTM International publish methods for measuring fabric weight, which is where the gsm figure comes from.
How Fabric Weight Changes the Quantity
For the same pattern and wastage, kilograms rise in direct proportion to gsm. The table shows the T-shirt in the example at four fabric weights, per piece and per thousand pieces. Length per piece does not change, because it depends only on the area and the width.
Fabric per T-shirt at different fabric weights (70 cm body, 22 cm sleeve, 52 cm chest)
| Fabric weight (gsm) | Kilograms per piece | Kilograms per 1,000 pieces |
|---|---|---|
| 140 | 0.166 | 166 |
| 180 | 0.213 | 213 |
| 220 | 0.260 | 260 |
| 280 | 0.331 | 331 |
Calculated with 4 cm allowances, 10% wastage and 150 cm width. Illustrative measurements; use your own pattern.
A switch from 180 to 280 gsm adds more than half again to the fabric weight. Because most knit fabric is priced per kilogram, that goes straight into cost. Our guide to fabric GSM for T-shirts and hoodies explains what the weight does for feel and drape, and the GSM calculator checks a swatch.
What Wastage Does to the Budget
Wastage covers fabric lost between the roll and the finished garment: gaps between pattern pieces, the ends of the spread, defects cut out and sampling. It is the most uncertain input, and the table shows how much it matters for 1,000 T-shirts at 180 gsm.
Fabric for 1,000 T-shirts at different wastage
| Wastage | Kilograms per piece | Kilograms per 1,000 pieces |
|---|---|---|
| 0% | 0.194 | 194 |
| 5% | 0.203 | 203 |
| 10% | 0.213 | 213 |
| 15% | 0.223 | 223 |
| 20% | 0.232 | 232 |
Calculated for the example T-shirt at 180 gsm and 150 cm width. Wastage percentages are illustrative, not typical values.
Fabric for 1,000 T-shirts in kilograms by wastage
Kilograms
Arithmetic from the example T-shirt: 193.5 kg of cloth in the garments before wastage. Wastage percentages are illustrative.
Each extra five points of wastage adds about ten kilograms to the example order. Ask your factory what wastage it assumes and why, because a tight marker can save more than a negotiation on price.
Where the Fabric Goes in the Example
With 10 per cent added for wastage, a tenth of the cloth the factory cuts is not in the garment. The pie shows the split of the cloth for one T-shirt, which is smaller than a tenth because wastage is added on top of the garment area.
Share of cut fabric that ends up in the garment
- In the T-shirt (0.194 kg)90.9%
- Wastage (0.019 kg)9.1%
Arithmetic: 10% wastage added to the garment area gives 1.0 ÷ 1.1 = 90.9% in the garment and 9.1% wasted. Illustrative wastage.
The wasted slice is paid for like the rest. Reducing it is a pattern and marker job, not a price negotiation, which is why our guide to the cost of making a T-shirt treats fabric efficiency as a cost driver.
A Hoodie Example
Hoodies use more cloth than T-shirts, partly through weight and partly through area. Take a 68 centimetre body, a 62 centimetre sleeve and a 58 centimetre flat chest in 320 gsm fabric, 150 centimetres wide, with the same allowances and 10 per cent wastage. Before the hood, pockets and cuffs, the calculator gives 0.585 kilograms and 1.22 metres per piece.
Hoodie body and sleeves before hood, pockets and cuffs
| Measure | Value |
|---|---|
| Body length | 68 cm |
| Sleeve length | 62 cm |
| Flat chest width | 58 cm |
| Fabric weight | 320 gsm |
| Garment area (before extras) | 1.662 m² |
| Fabric per piece with 10% wastage | 0.585 kg |
| Fabric length at 150 cm width | 1.22 m |
Illustrative measurements. Hood, pockets, cuffs and rib are not included; add them in the extra panels box.
Rib for cuffs and hem is usually a different fabric, so budget it separately. For the full cost of a hoodie, see our guide to the cost of making a hoodie.
Questions to Ask About Fabric Consumption
A quote is easier to trust when you know where the fabric figure came from. Ask the factory for the fabric consumption and what sits behind it.
What to ask a factory about fabric consumption
- Is the consumption from a marker or an estimate?
- What wastage is assumed, and for which sizes?
- Is the width used the full or the usable width?
- Does the figure include shrinkage allowance?
- Are rib, trims and linings counted separately?
- How does consumption change across the size range?
A general checklist. Your factory confirms what applies to your pattern.
Shrinkage matters because fabric that shrinks after cutting changes the finished size, which the fabric shrinkage calculator helps you plan for. If the fabric is bought by weight and you need the length, use the fabric kilograms to metres calculator.
How Ruhrose Helps You Understand Consumption
Ruhrose develops hoodies, fleece, jersey, denim and woven casualwear for UK buyers, with production in Bangladesh. We explain the main drivers of fabric use, such as pattern, size range and fabric weight, and sample before bulk so that the pattern is confirmed before a quantity is committed. Ruhrose's clothing manufacturing pages show what we make.
Before you accept a fabric figure, ask yourself one question: does anyone know where it came from?