Paint & Coating
Pigment volume concentration, coverage, and viscosity-dilution math.
How to use this tool
Two coating calculations in one. The Coverage tab tells you how far a litre of paint goes and how much to buy; the PVC tab checks the pigment loading that drives gloss and durability. Switch tabs at the top of the form.
What to enter
- Volume solids: % of the wet paint that stays behind as dry film (the rest is solvent that evaporates).
- Dry-film thickness: target thickness of the cured coat, in µm.
- Practical loss: % lost to overspray, substrate texture and waste.
- Area to coat: m² of surface, to size the order.
- PVC tab: enter the pigment volume and binder volume (same units) to get the pigment volume concentration.
Reading the result
Coverage mode gives practical and theoretical spread rate (m²/L) and the litres needed for your area. PVC mode gives the pigment volume concentration % with a gloss/durability verdict, staying below the critical PVC (~45–55%) keeps sheen and toughness.
Worked example
A paint at 40% volume solids applied at 50 µm covers 8 m²/L in theory, 6.4 m²/L after 20% loss, so a 100 m² job needs about 15.6 L.
Result
In Coverage mode the headline is the practical spread rate (theoretical minus your loss factor); the theoretical figure and the litres to buy for your area sit below it. In PVC mode the headline is the pigment volume concentration with a colour-coded verdict, staying below the critical PVC (~45–55%) keeps gloss and durability, while going above it gives a flat, porous film. Both are clean-substrate estimates; confirm spread rate on a test panel before ordering in bulk.
Coverage & pigment volume concentration
Theoretical coverage (m²/L) = 1000 × volume-solids fraction ÷ dry-film thickness (µm), before a practical-loss factor for overspray and substrate. PVC = pigment volume ÷ (pigment + binder volume). The critical PVC (CPVC) is where binder just fills voids between pigment; above CPVC the film loses gloss and gains porosity. Staying below CPVC keeps durability and sheen.
Sources
- Coatings technology handbooks; ASTM D2697 (volume solids), PVC/CPVC theory (Asbeck-Van Loo).