Anti-Fouling Paint Calculator

Theoretical volume assumes zero paint waste -- every drop that leaves the can ends up on the hull at exactly the target thickness. In reality, no application method achieves 100% transfer efficiency: some paint is lost to overspray, drips, roller retention, or spray bounce-back. Practical volume divides the theoretical figure by your chosen transfer efficiency percentage, which is why it's always larger -- it's the real amount you need to purchase to actually achieve full coverage after accounting for that waste.

Roller and brush application put paint almost directly where you want it, with relatively little material lost -- typically around 90-95% transfer efficiency. Airless spray is much faster for large hull areas but inherently wastes more paint to overspray (paint that misses the target surface) and bounce-back off the surface, commonly landing closer to 65% transfer efficiency. The trade-off is speed and finish quality versus material efficiency, so the right method depends on your priorities for a given job.

Dry film thickness (DFT) is the thickness of the coating after the solvent has fully evaporated and the paint has cured -- it's the figure that determines antifouling performance and lifespan, but it can only be verified after the paint dries. Wet film thickness (WFT) is the thickness of the paint immediately after application, while it's still full of solvent, and it's what you can actually check in real time with a wet-film gauge during application to confirm you're on track to hit your target DFT once it dries.

Volume solids is the percentage of the wet paint that remains as solid film after the solvent evaporates -- the rest evaporates away and contributes nothing to the final coating thickness. A paint with a higher volume-solids percentage packs more actual solid coating material into each liter of wet paint, so it takes less total wet volume to build the same dry film thickness across your hull compared to a lower-solids paint.

A single coat is more prone to pinholes, thin spots, and inconsistent coverage from the underlying surface texture or minor application variation, any of which can leave small areas under-protected and vulnerable to fouling or corrosion. A second coat covers gaps the first coat missed and builds the coating up to the full target dry film thickness more reliably, which is why most antifouling paint manufacturers recommend a minimum of two coats regardless of how carefully the first one is applied.