Art and Craft Supplies
Paint mixing ratios.
Write the recipe as parts and say how much you need. Get the amount of each colour to measure out, and scale it up or down without redoing the sums.
Amount of a colour = total x its parts / all parts. A 4 : 1 mix of white to blue for 250 mL is 200 mL white and 50 mL blue.
Recipe in parts
Amounts to measure
Fill the form and press Calculate.
Worked example
A recipe of 4 parts white to 1 part blue, needed as 250 mL. The parts add to 5, so white is 250 x 4 / 5 = 200 mL and blue is 250 x 1 / 5 = 50 mL. For a three-colour mix of 2 parts red, 3 parts yellow and 1 part white where you already have 30 mL of yellow, one part is 30 / 3 = 10 mL, so you need 20 mL red and 10 mL white, 60 mL in all. One US cup of a 3 : 1 mix is 0.75 cup and 0.25 cup, or 177 mL and 59 mL.
How it works
A ratio in parts is a share of the whole. Add the parts to get the whole, and each colour gets its parts divided by the whole times the total you want. To scale from an amount you already have, divide it by that colour's parts to get the size of one part, then multiply for every other colour.
The parts here are volumes of paint as measured, so keep the same measure (a spoon, a syringe or a cup) for every colour. The calculator does not predict the colour you will get: pigments, brands and binders behave differently, and a recipe that works with one range may not with another. Always mix a test patch.
Sources and basis (opened 2026-10-08): 1 US fl oz = 29.5735295625 mL from Fluid ounce (Wikipedia); 1 US cup = 8 US fl oz = 236.5882365 mL from Cup (unit) (Wikipedia).
FAQ
How do I mix paint at a 3:1 ratio?
Measure 3 equal parts of one colour and 1 of the other. For one US cup in total that is 0.75 cup and 0.25 cup.
How much of each colour for 250 mL at 4:1?
200 mL of the first and 50 mL of the second.
Can I scale a recipe if I only have a little of one colour?
Yes, choose the second option and enter what you have. In the example, 30 mL of yellow at 3 parts means 10 mL per part and 60 mL in total.
Will the ratio give the same colour every time?
Only with the same paints. Different pigments have different strengths, so test a patch and let it dry before mixing a large batch.
Does it work for resin or glaze?
It does the arithmetic for any liquid mixed by volume parts. For resin and other reactive mixes, follow the maker's ratio exactly and measure carefully.
Disclaimer
Results are arithmetic from the numbers you enter. It does not predict colour. Always test a small batch, and follow the manufacturer's mix ratio exactly for resins and other reactive products.