When to use this guide
Use it to estimate how many 25 kg cartons a job needs, to compare quotes on a cost-per-square-metre basis, or to check whether a line is over-building film.
What you need
- Specific gravity from the TDS of the chosen powder
- Target dry film thickness (WANAN recommends 80–120 µm)
- Total area to be coated, in m²
Steps
Find the specific gravity
Take the specific gravity (g/cm³) from the TDS of the exact grade and colour you will use.
Choose the film thickness
Use the dry film thickness you will actually apply, within the recommended 80–120 µm.
Apply the formula
Coverage (m²/kg) = 1000 ÷ (specific gravity × µm). Example: 1000 ÷ (1.5 × 100) ≈ 6.7 m²/kg.
Convert to cartons
Divide the total area by the coverage to get kilograms, then by 25 to get the number of 25 kg cartons.
Allow for the real line
Theoretical coverage assumes every gram ends up on the part. Transfer efficiency, reclaim and part geometry change the real figure, so compare with your own consumption records.
Key values
| Item | Value | Source |
|---|---|---|
| Formula | 1000 ÷ (SG × µm) = m²/kg | Powder coating 101 |
| Worked example | SG 1.5, 100 µm → about 6.7 m²/kg | Powder coating 101 |
| Recommended film | 80–120 µm | Series TDS |
| Packing | 25 kg cartons | Series TDS |
Common mistakes
- Using a generic specific gravity instead of the grade’s TDS value
- Calculating at 80 µm when the line actually runs 120 µm
- Comparing powders by price per kg instead of cost per m²
- Blending reclaimed powder without a controlled ratio
Related
Published 7 October 2026 by the WANAN technical team. Figures are taken from WANAN technical data sheets and the pages linked above.