Cluster article
Flour Mill Operating Cost: The Full Breakdown by Line Item
Operating cost structure for a wheat flour mill — wheat, labour, power, maintenance, packaging and overheads — with a worked 60 t/d example and the levers that move each line.
Key takeaways
- Wheat is 65–80% of operating cost. Nothing else is remotely close.
- Labour per tonne falls steeply with scale: 3 people per shift at 20 t/d, 8 at 200 t/d.
- Packaging is 3–5% and often underestimated because bag costs vary 3× by specification.
The structure
| Line | Share | Controllable? |
|---|---|---|
| Wheat | 65–80% | Partly (buying, blending) |
| Labour | 5–10% | Yes |
| Power | 5–8% | Yes |
| Packaging | 3–5% | Yes |
| Maintenance & spares | 3–5% | Yes |
| Overheads | 2–4% | Partly |
Worked example — 60 t/d plant
Assumptions: 330 operating days, 76% extraction, wheat at USD 280/t, power at USD 0.10/kWh, 12 staff.
| Line | Basis | Annual (USD) | Per tonne flour |
|---|---|---|---|
| Wheat | 19,800 t × 280 | 5,544,000 | 368.4 |
| Labour | 12 staff | 95,000 | 6.3 |
| Power | 853,000 kWh | 85,300 | 5.7 |
| Packaging | 602k bags | 210,672 | 14.0 |
| Maintenance | 4% of equipment | 12,000 | 0.8 |
| Overheads | admin, insurance, transport | 85,000 | 5.6 |
| Total | 6,031,972 | 400.8 |
Revenue: flour 15,048 t × 400 = 6,019,200, plus bran 3,960 t × 120 = 475,200. Total 6,494,400.
Gross margin: USD 462,428 — about 7.1%. Better than the 3% in the pillar example because bran recovery and packaging are modelled more favourably here; real projects land somewhere in between depending on local prices.
Labour by scale
| Capacity | Staff per shift | Annual cost (typical) |
|---|---|---|
| 20 t/d | 3 | USD 40,000–70,000 |
| 30 t/d | 3–4 | USD 50,000–85,000 |
| 60 t/d | 4–6 | USD 80,000–140,000 |
| 100 t/d | 6–8 | USD 120,000–210,000 |
| 200 t/d | 8–12 | USD 190,000–340,000 |
| 300 t/d | 12–18 | USD 280,000–500,000 |
Labour per tonne falls from roughly USD 9/t at 20 t/d to USD 5/t at 200 t/d. This is one of the main scale advantages.
Power
Covered in detail in the power consumption article. Key figures:
- 65–74 kWh per tonne of flour
- Falls with plant scale
- Roll condition has the largest controllable effect after system tuning
Packaging
Widely underestimated. Bag cost varies enormously:
| Bag type | Cost per 50 kg bag | Per tonne of flour |
|---|---|---|
| Woven PP, unprinted | USD 0.20–0.32 | USD 4–6.4 |
| Woven PP, printed 4-colour | USD 0.38–0.55 | USD 7.6–11 |
| Multiwall paper | USD 0.45–0.75 | USD 9–15 |
| Cotton / jute | USD 1.10–2.00 | USD 22–40 |
| 25 kg retail printed | USD 0.30–0.50 | USD 12–20 |
A mill switching from unprinted PP to 4-colour printed bags adds 3–5% to operating cost. That is often worth it for a branded retail product and rarely worth it for bulk bakery supply.
Maintenance
Budget 3–5% of equipment value per year:
| Equipment value | Annual maintenance |
|---|---|
| USD 100,000 | USD 3,000–5,000 |
| USD 300,000 | USD 9,000–15,000 |
| USD 800,000 | USD 24,000–40,000 |
| USD 1,500,000 | USD 45,000–75,000 |
Under-budgeting maintenance is the classic path to a plant that runs well for three years and then fails catastrophically.
The levers ranked by impact
| Lever | Annual impact (60 t/d) |
|---|---|
| +1% extraction | +USD 79,000 |
| −5% wheat cost | +USD 277,000 |
| +3% flour price | +USD 181,000 |
| −10% power | +USD 8,500 |
| −10% labour | +USD 9,500 |
| −10% packaging | +USD 21,000 |
Extraction dominates everything you control inside the plant. It is worth more than eliminating your entire power bill.