Understanding your result
The headline gives the ratio and the amount of each paint, and the sub-line the total. The figures repeat each paint’s amount.
The table shows each paint with its parts and its percentage of the mix, then the total. In the second mode the arithmetic panel starts with the total that the paint you have makes, then splits it. Small amounts appear in fluid ounces (millilitres in metric), larger ones in quarts and gallons.
Mixing turns leftovers and samples into useful paint. The leftover paint planner deals with what is in the garage; the sample pot calculator sizes a colour test; the quantity converter turns the results into any unit; and the thinning calculator covers the different job of adding water or solvent.
How we calculate this
The arithmetic is exact and works in any unit; the calculator converts with the exact factors on the can sizes and conversions reference (128 fl oz to a US gallon, 3.785 litres). The dark colours guide explains why a little of a deep colour shifts a light one a lot, which is the usual surprise in mixing, and the can sizes guide covers what to do with the leftovers mixing is often used for.
The assumptions behind the numbers
| Assumption | Value | Where it comes from |
|---|---|---|
| Ratio | by volume | Paint is measured and sold by volume |
| US gallon | 4 quarts, 128 fl oz | US customary definitions |
| Litre | 1,000 mL; 3.785 L per US gallon | SI and the US gallon definition |
| Default | 3 : 1, one gallon | An example ratio |
Assumptions last reviewed October 8, 2026.
The calculator mixes by volume and assumes the paints blend. It cannot predict the colour, which depends on the pigments, or check that the products are compatible; the notes and a test patch do that.
Two worked examples
Lightening a colour 3 to 1 for a gallon
- Total parts: 3 + 1 = 4; each part a quart
- Paint A: 3 quarts; paint B: 1 quart
Working from 3 quarts of paint A that you already have, the same ratio gives a gallon in all, with one quart of B to add.
Three paints and a small test
Three paints at 2 : 1 : 1 for 2 gallons: 1 gallon, 2 quarts and 2 quarts.
A quart test batch at 5 : 1 is 26.7 fl oz and 5.3 fl oz. In metric, 4 litres at 3 : 1 is 3 litres and 1 litre.
Where to find your inputs
Parts. From a recipe, a previous mix written on a can, or a test you liked.
Total or what you have. The volume the job needs, from a quantity calculator, or what is in the can of the main paint.
Common mistakes
- Mixing latex with oil paint. They do not combine.
- Mixing different sheens. The result is unpredictable.
- Mixing a second batch later. It will not match; mix it all at once.
- Not writing down the ratio. Touch-ups need it.
- Small batches measured by eye. Use a measuring jug.
- Buying two full cans to mix a third colour. Ask the store to tint it.
Questions people ask
- How do I mix paint in a ratio?
- Add the parts to get the total parts, divide the volume you want by that total, and multiply by each paint's parts. For a 3 to 1 mix in a gallon, there are 4 parts of a quart each, so 3 quarts of the first paint and 1 quart of the second.
- I have 3 quarts of one paint. How much of the other for 3 to 1?
- One quart, giving a gallon in all. The calculator's second mode works from the paint you have and gives the others and the total.
- Can I mix two different paints?
- If they are the same type, latex with latex or alkyd with alkyd, and ideally the same product line and sheen. Different sheens mix to an unpredictable sheen, and different lines can differ in hiding and durability.
- Will the mixed colour be even?
- Only if you mix the whole job's quantity at once and stir it thoroughly. A second batch mixed by eye will not match exactly; write the ratio on the can.
- Is mixing cheaper than buying a custom colour?
- Rarely, unless you are using leftovers. A paint store can match a mixed sample on its tinting machine, give you the formula and mix more later. Mixing two full-price paints to get a third costs more than buying the third.
- How do I measure small amounts?
- In fluid ounces or millilitres, with a kitchen measuring jug kept for paint. For a sample, a 5 to 1 ratio in a quart is 26.7 fl oz and 5.3 fl oz.