How much paint you actually need for an army (and why "eyeballing it" runs out mid-batch)

Every miniature painter who has mixed a custom color knows the specific frustration: you match a shade perfectly on the first model, run out two-thirds of the way through a ten-model unit, and mix a second batch that is close but never quite identical. The last three models in the squad are visibly a slightly different shade under table lighting, and there is no fixing it short of repainting the whole unit. The fix is not a better eye for color matching — it is mixing the entire batch's worth of paint before the brush ever touches the first model, and that requires knowing how much paint the whole unit actually needs.

Paint consumption per model depends on scale, and it is not a small difference

A standard 28mm infantry model is the baseline unit of paint consumption. A large monster or vehicle model has roughly four times the surface area to cover, so it consumes roughly four times the paint per model. A terrain piece — a ruin, a hill, a bunker — has roughly twelve times the surface area of a single infantry model. These are not small adjustments: a batch sized for ten infantry models will not come close to covering even three large monster kits, and painters who scale their mix by "number of models" rather than "number of models times surface area" are the ones who run dry mid-project.

Coverage type is the second multiplier, and it cuts the other way

How you're applying the paint matters just as much as what you're applying it to. A basecoat needs full, opaque coverage — every surface, no shortcuts — and consumes paint at the baseline rate. A layering pass, applied thinly over an existing basecoat to build highlights, needs only about 40% as much paint per model, because you are covering less area with a thinner application. Drybrushing — dragging a nearly-dry brush across raised edges to catch highlights — needs only about 20% as much, since it is deliberately depositing paint on a small fraction of the model's surface. A drybrush highlight pass on an entire terrain piece can use less paint than a basecoat on a single infantry model, once both multipliers are accounted for.

The ratio has to survive scaling up, not just taste right in a test drop

Custom colors are usually built as a ratio — say, 3 parts of one color to 1 part of a second color to 2 parts water or thinner — tested on a palette in a handful of drops before committing to the whole batch. The mistake is testing the ratio at a small scale and then eyeballing a "bigger version" of it for the real batch, which is exactly where proportions drift. The fix is arithmetic, not intuition: figure out the total drops of finished paint the whole batch needs, then split that total across the ratio's parts proportionally, rounding each part up rather than down. Rounding down risks running dry on the last color right before the batch is finished; rounding up costs at most a spare drop or two of already-cheap paint.

Worked example: a ten-model squad versus a five-model vehicle unit

Twenty standard infantry models getting a full basecoat, mixed at a 3:1:2 ratio (main color to accent color to water), come out to about 16 total drops of finished paint — a little under a full milliliter. Split across the ratio, that is 8 drops of the main color, 3 drops of the accent, and 6 drops of water, for the whole squad in a single mixed batch.

Now compare five large vehicle models getting a thin layering pass at a 4:1:1 ratio. Despite having a quarter of the model count of the infantry squad, the size multiplier for large models is high enough that the batch still needs about 7 total drops — only slightly less than a squad four times its size, because each vehicle is covering roughly as much surface as several infantry models even with a thinned layering coat. Split 4:1:1, that comes out to 5 drops of the main color and 2 drops each of accent and water. Skipping the scale multiplier here — mixing "five models' worth" the way you would for five infantry models — would leave you significantly short before the last vehicle is even half covered.

Mix once, mix slightly over, and keep the leftover

Because drops are cheap and a second mixing session is the actual failure mode you are trying to avoid, round every part of the ratio up rather than down, and treat the total as a floor rather than a target. A few extra drops of already-mixed paint cost nothing and keep in a sealed palette well or wet palette for touch-ups days later; running out mid-model and needing to re-derive the exact ratio from memory is the scenario the whole batch calculation exists to prevent.

Our miniature paint mix and volume calculator takes your model count, scale, coverage type, and custom ratio, and returns the exact number of drops of each component — plus the total volume in milliliters — so the whole unit gets mixed in one batch instead of a color-matching guessing game halfway through.