Washing cost is one of the most frequently underestimated line items in garment production costing in Bangladesh. Many factories quote a flat washing rate without fully accounting for every input — and then wonder why the department consistently runs over budget. This guide breaks down every component that goes into a proper cost-per-piece calculation for a washing plant.
The Main Cost Components
A complete washing cost sheet covers six primary categories: labour, chemicals, water, steam/fuel, overhead (machine depreciation, maintenance, utilities), and ETP (Effluent Treatment Plant) operating cost. Missing any one of these produces an understated cost that distorts both pricing and profitability.
Typical Washing Cost Components — Bangladesh Denim Wash
| Component | Approximate Share | Notes |
|---|---|---|
| Labour (operators, helpers, QC) | 20 – 28% | Based on daily output and headcount |
| Chemicals (enzymes, dyes, softeners) | 25 – 35% | Highest variability — depends on wash type |
| Water (intake + discharge) | 8 – 12% | Includes WASA charge and drainage cost |
| Fuel (gas/HFO for boiler) | 10 – 15% | Steam for tunnel finisher and drying |
| Electricity | 8 – 12% | Washing machines, dryers, compressors |
| ETP operating cost | 5 – 8% | Chemicals, power, labour for effluent treatment |
| Overhead and depreciation | 8 – 12% | Machine cost spread over useful life |
Labour Cost Per Piece
Labour cost per piece depends on how many garments the plant can process per shift and how many workers are required. A mid-sized washing plant in Bangladesh running one 8-hour shift with 60 workers processing 3,000 pieces per day has a per-piece labour cost calculated as follows.
Labour cost per piece = (Total daily labour cost) / Daily output Example: 60 workers × ৳650 avg daily wage = ৳39,000/day Daily output = 3,000 pieces Labour cost per piece = ৳39,000 / 3,000 = ৳13 per piece
Chemical Cost — The Most Variable Component
Chemical cost depends entirely on the wash type. A basic enzyme wash uses far fewer inputs than a heavy stone-enzyme or bleach wash. Chemical consumption is typically expressed in grams per kilogram of fabric, and the cost is calculated from the chemical price per kg and the weight of garments per batch.
Approximate Chemical Cost Ranges by Wash Type
| Wash Type | Chemical Cost Range per Piece (BDT) | Notes |
|---|---|---|
| Normal wash (softening only) | ৳3 – ৳6 | Softener, anticreasing agent only |
| Enzyme wash | ৳8 – ৳15 | Cellulase enzyme, neutraliser, softener |
| Bleach wash | ৳12 – ৳20 | Sodium hypochlorite, antichlor, softener |
| Stone enzyme | ৳15 – ৳25 | Pumice stone, enzyme, softener — high wear on machines |
| Denim tinting / overdye | ৳20 – ৳40 | Reactive or vat dyes plus all auxiliary chemicals |
ETP Cost — Often Missed Entirely
The Effluent Treatment Plant is a legal requirement for any export washing plant in Bangladesh. Its operating cost — chemicals for pH neutralisation, coagulants, flocculants, power, and ETP operators — must be included in the per-piece cost. A well-run ETP treating 500 m³ of effluent per day typically costs ৳4–8 per m³ to operate, which translates to ৳2–5 per piece depending on water usage per garment.
Tip
Always cost your washing rate at 85–90% machine capacity utilisation, not 100%. Machines are down for maintenance, style changeovers, and rinsing cycles. Costing at 100% means your actual rate will always exceed your quoted rate when utilisation falls — which it always does.