Paint Color Mixing Ratio Calculator
Split a batch of paint into two colors by a mixing ratio, or work out the ratio you already have — for a repeatable custom shade.
How it works
Color A = total × A ÷ (A + B) · Color B = total × B ÷ (A + B)
A mixing ratio divides the batch into A + B equal parts, then hands each color its share of the total. Because both amounts come from the same total, they always add back to the batch size exactly. Keeping the ratio fixed is what lets you reproduce the same shade at any batch size — 3:1 gives the identical color whether you mix 100 ml or 10 litres.
Worked example
To make 1,000 ml at a 3:1 ratio, there are 3 + 1 = 4 parts. Color A gets 3/4 × 1,000 = 750 ml and color B gets 1/4 × 1,000 = 250 ml, which add back to the full 1,000 ml.
Frequently asked questions
How do I keep a custom color consistent between batches?
Always mix by the same ratio, not by eye. Record the parts (for example 3:1) and scale them to whatever total you need; the ratio, not the volumes, is what fixes the shade.
Can I use any unit for the parts?
The parts are unitless — only their proportion matters. Measure the final volumes in whatever unit you set as the total (ml, ounces, litres); just keep everything in that one unit.
Does this work for tinting a base with colorant?
Yes. Treat the base as color A and the colorant as color B. Colorant ratios are often small (like 20:1), which this handles the same way — the base takes 20/21 of the batch and the tint 1/21.
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This calculator is for educational purposes. Double-check important results before acting on them.