Paint Dilution Calculator — Paint to Thinner Ratios

A typical acrylic wash uses about 1:3 to 1:5 (paint:thinner) — roughly 17–25% paint. For a very light, transparent wash go to 1:10; for a more opaque wash with visible brush strokes stay around 1:2. The presets, results and How it works section above are all written paint-first; where a FAQ below quotes a water-first ratio it says so explicitly. Adding a flow medium instead of pure water helps maintain paint film integrity at high dilutions.

You can thin acrylics with water up to about 30% (roughly 1:3 water to paint ratio) without problems. Beyond that, the paint film becomes weak and may crack or not adhere properly. For thinner applications, use an acrylic medium or flow improver instead of pure water.

Fat over lean means each successive layer of oil paint should contain more oil (fat) than the layer below. This prevents cracking as the painting dries. Start with more turpentine and less oil in lower layers, gradually increasing the oil content in upper layers.