NTB SpecPro

Paint consumption and wet film thickness calculator

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Free tool · Paint

Paint consumption and wet film thickness calculator

Enter the area, the required dry film thickness (DFT) and the volume solids of the paint; theoretical and practical litres, spreading rate and wet film thickness (WFT) are calculated instantly. Everything runs in your browser.

Also available in: Türkçe · العربية

Theoretical consumption– L
Practical consumption– L
Wet film thickness WFT– µm
Theoretical spreading rate– m²/L

Theoretical L = area × DFT × coats / (volume solids × 10) · Practical L = theoretical / (1 − loss) · WFT = DFT × (100 + thinner) / volume solids · Spreading rate = volume solids × 10 / DFT

The loss factor depends on the application method and the part shape: 10–20 % for brush/roller on simple surfaces, 20–40 % for airless spray, more on complex steel structures. Adding thinner lowers the volume solids, so a thicker wet film is needed for the same DFT. Take the values from the paint's technical data sheet.

For information only; the paint manufacturer's technical data sheet and the specification govern. The final assessment rests with the responsible paint/coating specialist.

Let the app record your DFT readings and adhesion testsThe Paint module records DFT readings, adhesion tests and visual inspection and prepares the PDF report.
Try the Paint module

Curious?

What does volume solids mean?It is the share of the paint's volume that remains as film after drying. With 60 % volume solids, a 100 µm wet film leaves about 60 µm of dry film. It appears as "volume solids" on the data sheet; do not confuse it with solids by weight.
Why is the loss factor so high?In spraying, part of the paint never reaches the part (overspray), part stays in the pot and hoses, and complex shapes get extra thickness. That is why suppliers give a practical value next to the theoretical spreading rate.
What is a wet film comb for?Measuring with a WFT comb while the paint is still wet shows at once whether the target DFT will be reached; correcting after drying means another coat. This tool gives the target WFT value.
How do I record dry film measurements?DFT readings are kept per part and area, together with the gauge calibration. The Paint module of the app keeps DFT readings, the adhesion test and visual inspection in one record and produces the PDF report.

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