Free tools/Yarn & Fabric
Knit Fabric Consumption Calculator
Calculate T-shirt and knit top fabric consumption in kg per dozen from body length, sleeve length, chest and GSM. The formula, a worked example and a table of kg per dozen from 140 to 240 GSM.
Fabric per dozen
2.534kg
Fabric per piece
0.2112kg
Pieces per kg
4.73
The formula
kg/dozen = (body length + sleeve length + allowance) x (half chest + allowance) x 2 x GSM x 12 / 10,000,000, plus wastage.
Worked example
Body length: 70 cm, Sleeve length: 25 cm, Chest width (half chest): 55 cm, Allowance: 5 cm, Fabric GSM: 160 g/m2, Wastage: 10 %. Result: Fabric per dozen = 2.534 kg; Fabric per piece = 0.211 kg; Pieces per kg = 4.73.
How to calculate T-shirt fabric consumption
Measure the garment in centimetres: body length (high point shoulder to hem), sleeve length and half chest (chest width laid flat). Add a sewing and cutting allowance to the length and to the width.
Multiply length by width to get one panel, then by 2 for front and back. Multiply by GSM to get grams per piece, by 12 for a dozen, and divide by 10,000,000 to turn square centimetres and grams into kilograms. Add wastage last.
Worked example: (70 + 25 + 5) x (55 + 5) x 2 x 160 x 12 / 10,000,000 = 2.304 kg per dozen. With 10% wastage that is 2.534 kg per dozen, 0.211 kg per piece.
This is a pre-costing estimate from measurements. The figure you buy against should come from the marker once the pattern is made, because nesting, size ratio and fabric width change the real consumption.
Fabric consumption by GSM (kg per dozen)
| GSM | kg per dozen | kg per piece | Pieces per kg |
|---|---|---|---|
| 140 | 2.218 | 0.185 | 5.41 |
| 160 | 2.534 | 0.211 | 4.73 |
| 180 | 2.851 | 0.238 | 4.21 |
| 200 | 3.168 | 0.264 | 3.79 |
| 220 | 3.485 | 0.290 | 3.44 |
| 240 | 3.802 | 0.317 | 3.16 |
Kg per dozen for the worked example (body 70 cm, sleeve 25 cm, half chest 55 cm, 5 cm allowance, 10% wastage) at different fabric weights, computed with this calculator.
Assumptions
- Measurement-based estimator for pre-costing; final consumption comes from the marker.
- Front and back panels covered by the x2; sleeves inside the length term.
- Wastage applied as a flat percentage.
Questions
- What is the formula for T-shirt fabric consumption?
- kg per dozen = (body length + sleeve length + allowance) x (half chest + allowance) x 2 x GSM x 12 / 10,000,000, then add wastage. All lengths in cm.
- How much fabric does a T-shirt need?
- It depends on size and GSM. A T-shirt with a 70 cm body, 25 cm sleeve and 55 cm half chest in 160 GSM jersey needs about 2.53 kg per dozen with 10% wastage, or 0.21 kg per piece.
- How does GSM change fabric consumption?
- Consumption in kg rises in direct proportion to GSM. The same T-shirt in 180 GSM uses 12.5% more fabric by weight than in 160 GSM, because the area is the same and each square metre weighs more.
- Is this the same as marker consumption?
- No. This is a measurement-based estimate for costing before the pattern exists. Marker consumption comes from the actual marker and replaces this figure for fabric booking.
Read the guide
In the platform
Intelactory records which yarn lot went into which fabric roll, dye batch and carton as the work happens, so a count or GSM question traces back to its source.