About this tool
The Paint Mix Ratio Calculator splits a batch of automotive paint into its base, hardener (activator), and reducer parts according to a mixing ratio such as 4:1:1 or 8:1. Two-component (2K) paints, clearcoats, and primers must be catalysed in exact proportions — the ratio printed on the can (paint : hardener : reducer) determines how the product cures, so mixing it accurately is essential for gloss, hardness, and durability.
Enter the ratio as up to three colon-separated parts. Given a target total volume T, each component is T × part ÷ sum(parts). Alternatively, if you already have a fixed amount of one component — say you poured a known volume of base — the tool computes a unit of "one part" as that volume ÷ its part number, then multiplies each part by that unit, so the whole batch scales exactly to what you have. Results are shown in your chosen unit (millilitres or fluid ounces) for every component plus the total mixed volume.
Everything runs locally in your browser with no uploads. Always follow the technical data sheet for your specific product: ratios are by volume unless the sheet states by weight, and reducer or activator choice depends on temperature and panel size. Measure with a graduated mixing cup or ratio stick, mix thoroughly, and observe the product's pot life once catalysed. This tool handles the arithmetic; the paint manufacturer's spec is the authority on the numbers.