La guía detallada está disponible temporalmente en inglés.
How much paint does a room actually need?
One gallon of interior paint covers roughly 350–400 square feet of smooth, primed wall in ideal conditions. Textured surfaces, fresh drywall that has never been sealed, and big color changes all pull that number down, which is why the calculator lets you set the coverage yourself. When in doubt, plan on the lower figure — a half-used gallon on the shelf beats a second trip to the store with a roller still wet.
Why openings and coats change the math
Doors and windows are subtracted first because nobody paints glass — the standard approximations of 21 ft² per door and 15 ft² per window are close enough for ordering. Coats matter just as much: two coats is the norm for even color and a washable finish, and the calculator doubles the paintable area before dividing by coverage. For a dramatic dark over light walls, a tinted primer usually costs less than a third coat.
Contexto local: España
Datos locales de España, útiles para cálculos cotidianos:
- IVA: 21 % general (10 % hostelería, 4 % alimentos básicos), siempre incluido en el precio.
- Moneda y pagos: Euro (€); tarjeta sin contacto y Bizum muy extendidos.
- Unidades y números: Sistema métrico; coma decimal y punto de millar: 1.234,56 €.
- Nóminas: Costumbre de 14 pagas (extra en julio y diciembre) en salarios y algunas rentas.
- Propina: Voluntaria, 5–10 % o redondeo; el servicio va incluido en el precio.
Actualizado: octubre 2026 · valores de 2025, fuentes oficiales arriba.
Preguntas frecuentes
Does this include the ceiling?
No — the calculation covers walls only. For a ceiling, measure the floor area instead (they match in most rooms), and count on flat ceiling paint at the same coverage figure.
What coverage should I enter?
Keep 350 ft² per gallon for typical interior latex on primed walls. Drop to about 300 for heavy texture or bare drywall, and check the can — manufacturers print tested coverage that is usually in the 250–400 range.
How do the suggested can sizes work?
Gallons are rounded up to a whole number, then broken into 5-gallon buckets plus 1-gallon cans. Six gallons comes back as one 5-gallon bucket and one single gallon, which is usually cheaper than seven singles.