Running out of a key colour halfway through an army is one of the most frustrating hobby problems — especially with light colours that need several coats over dark primer, or discontinued paints that are hard to replace. This calculator converts your model count or terrain area into total surface area, applies a per-pot coverage rate, and tells you exactly how many whole pots to buy before you start.
How it works
The tool turns models into area, multiplies by coats, and divides by the coverage each pot provides:
total area = models × area_per_model(scale) (or terrain area directly)
paint area = total area × coats
pots = ceil( paint area / coverage_per_pot )Because each coat repaints the whole surface, the coat count multiplies directly. The per-pot coverage rate is configurable so you can dial in your own thinning and the opacity of a given colour — a thin glaze covers far more area than a thick base coat.
Scale and surface area reference
The tool assigns a typical paintable surface area to each scale category. These are approximate values based on the physical size of a standard trooper model:
| Scale | Typical model | Approximate paintable area |
|---|---|---|
| 10 mm (e.g. Warmaster) | Small infantry | ~4 cm² per model |
| 15 mm | Infantry | ~8 cm² per model |
| 28 mm (e.g. Warhammer 40K) | Infantry trooper | ~20 cm² per model |
| 32 mm (e.g. Warhammer Age of Sigmar) | Infantry trooper | ~28 cm² per model |
| Large monster / vehicle | Varies | Enter area directly |
For cavalry, monsters, or vehicles, switch to terrain mode and enter the surface area manually — these vary too much for a single per-scale estimate.
Worked example: a 40-model infantry unit
For example, imagine you are painting 40 Space Marines (28 mm scale) in a scheme that requires a light grey base colour over black primer. Light colours over dark primer typically need two or three coats for full opacity.
- 40 models at 20 cm² each = 800 cm² total surface.
- Two coats means 1,600 cm² of total coverage area.
- A standard 12 ml hobby paint pot at a typical coverage rate of 400 cm²/coat gives you 4 pots needed.
If you extend to three coats (common for off-white or bone colours), that becomes 6 pots — a significant difference when budgeting for a tournament army.
Tips on coverage rates and technique
The per-pot coverage rate has a wide range depending on how you work:
- Base coats, full coverage — lower coverage rate (more paint per cm²). Use the default or reduce it slightly.
- Drybrushing — very high coverage rate. A pot of drybrush paint goes much further than a base coat pot because so little stays on the brush.
- Washes and glazes — high coverage rate. A thin wash flows into recesses and covers large areas efficiently.
- Heavily thinned with medium or water — coverage rate increases, but you may also need an extra coat for opacity.
When buying paint for a long project, round up and buy an extra pot of any colour you use in large quantities. Matching a colour from a later batch is possible but the shade can differ slightly, and blending from two slightly different batches is visible on a large flat area like terrain.