🎨 Paint Thinning Ratio Calculator
Enter your desired total mixed amount and ratio (1:1 is a common 'milk consistency' starting point) to see exact paint and thinner amounts.
It works backwards from the total
You give the tool the mix you want to end up with, not the paint you started from. It splits that total into ratio parts:
per part = total drops / (paint parts + thinner parts)
paint = paint parts × per part
thinner = thinner parts × per partTen drops at the default 1:1 is 5.0 and 5.0. The same ten at 2:1 splits into three parts of 3.33, giving 6.7 drops of paint and 3.3 of thinner.
| Total | 1:1 | 2:1 | 1:2 |
|---|---|---|---|
| 6 drops | 3.0 + 3.0 | 4.0 + 2.0 | 2.0 + 4.0 |
| 10 drops | 5.0 + 5.0 | 6.7 + 3.3 | 3.3 + 6.7 |
| 12 drops | 6.0 + 6.0 | 8.0 + 4.0 | 4.0 + 8.0 |
Pick a total that divides cleanly - a multiple of three for 2:1 and 1:2 - or you are counting out two thirds of a drop.
Drops, and what to thin with
- A dropper bottle drop is about 0.05 ml, so 20 drops make 1 ml and the 10 drop default is half a millilitre.
- Water dilutes the binder too. Past roughly 1:1 with plain water the film turns weak and chalky. Flow improver and thinner medium carry binder, so use those below that point.
- Distilled water, not tap. Hard water leaves lime deposits in the film and can curdle some paints.
Frequently asked questions
What is a 1:1 paint to water ratio in drops?
Equal drops of each: 5 and 5 for a 10 drop mix, 6 and 6 for 12. That is the usual milk consistency starting point for brush basecoats.
How thin should paint be for an airbrush?
Thinner than for a brush - about 1:1 to 1:2 for most hobby acrylics, closer to skimmed milk, and thinner still through a 0.2 mm needle. Use airbrush thinner rather than water at that dilution.
What ratio should I use for a glaze?
1:2 or thinner, so 3.3 drops of paint to 6.7 of medium in a 10 drop mix. A glaze shifts the colour slightly over several passes; if one coat changes the tone completely it is still too thick.