Consumption formula
Body-block estimate of knit fabric weight per dozen basic T-shirts from body length, sleeve length, half chest, GSM and allowances.
kg/dozen = (body length + sleeve length + allowance) × (½ chest + allowance) × 2 × GSM × 12 / 10,000,000
| Symbol | Meaning | Unit |
|---|---|---|
| BL | Body length | cm |
| SL | Sleeve length | cm |
| ½C | Half chest | cm |
| a_L | Length allowances (hems and seams) | cm |
| a_W | Width allowances (side seams) | cm |
| GSM | Finished fabric weight | g/m² |
Use it for quick costing of basic T-shirts before a marker exists, then add the wastage percentage your factory uses for the style.
Body 70 cm, sleeve 20 cm, half chest 52 cm, length allowance 8 cm, width allowance 4 cm, 160 GSM.
The factor 10⁷ combines 10⁴ (cm² to m²) and 10³ (g to kg).
The body block method for calculating fabric consumption of a basic T-shirt in kg per dozen, with a worked example, how to handle neck rib, size ratios and wastage, and how to check the estimate against a marker.
How to calculate fabric consumption for knit garments (by weight, from panel areas and GSM) and woven garments (by length, from the marker), with worked examples, wastage allowances and the mistakes that cause fabric shortages.