Conditioned (Commercial) Weight Calculator
Turn dry weight into the invoiced commercial weight using the fibre’s commercial moisture regain.
| Fibre | Commercial weight (kg) |
|---|---|
| Polyester (0.4%) | 100.4 |
| Nylon (4.5%) | 104.5 |
| Cotton (8.5%) | 108.5 |
Frequently asked questions
What is commercial weight?
Commercial (conditioned) weight is the contractual, invoiced weight found by adding a fibre’s legal/commercial moisture regain (R) to its bone-dry mass. Formula: commercial = dry × (1 + R). Because moisture varies with air conditions, this standard weight is used instead of a raw weigh-in.
What is the moisture regain of polyester?
Polyester’s commercial moisture regain is 0.4%. It is so low that dry and commercial weight are almost identical: 100 kg dry polyester = 100 × 1.004 = 100.4 kg commercial. For comparison, nylon is 4.5%, cotton 8.5%, viscose 12% and wool 16.5%.
How do I find the invoice weight of a blended yarn?
First compute the weighted-average R from the fibre proportions, then apply commercial = dry × (1 + R). Example: for 65% polyester / 35% cotton, R = 0.65 × 0.004 + 0.35 × 0.085 = 0.032; 100 kg dry yarn → 103.24 kg commercial weight.
What is the difference between dry weight and actual weight?
Dry (bone-dry) weight is the fibre mass with all moisture removed; actual weight is the real, moist weigh-in at delivery. From actual to commercial weight: commercial = actual × (1 + R_commercial) ÷ (1 + R_actual).