Projetos de Interior

Calculadora de Tinta

Planejando pintar sua casa? Nossa calculadora gratuita descobre a quantidade exata de tinta necessária em litros ou galões.

⚡ Quick Dimensional Presets:

Medidas do Projeto

Digite as dimensões para calcular os materiais necessários

2D DRAFTING PLAN14 FT × 12 FT (168 SQ FT)

Insira as medidas acima para visualizar os resultados.

Exemplo Passo a Passo

Cenário: Painting a standard 12 ft × 15 ft bedroom with 8 ft ceilings, 1 door, 2 windows, and 2 coats of wall paint.

Calculate Perimeter: 2 × (12 + 15) = 54 linear feet.

Calculate Gross Wall Area: 54 ft × 8 ft height = 432 sq ft.

Deduct Openings: 1 door (20 sq ft) + 2 windows (30 sq ft) = 50 sq ft deduction.

Net Paintable Wall Area: 432 - 50 = 382 sq ft.

Factor in 2 Coats: 382 sq ft × 2 = 764 sq ft effective coverage needed.

Calculate Paint Volume: 764 sq ft ÷ 350 sq ft/gallon = 2.18 gallons.

Result: Purchase 3 gallons (or 2 full gallons plus 1 quart can) to guarantee continuous coverage with reserve for touch-ups.

Paint Quantity Formula

Total Paint (Gallons) = [ (Perimeter × Height) - Deductions + Ceiling Area ] × Coats ÷ Coverage Rate

Perimeter is calculated as 2 × (Length + Width). Gross wall area is Perimeter multiplied by Height. Openings (doors at 20 sq ft, windows at 15 sq ft) are subtracted from gross area to yield net paintable surface area. This net area is multiplied by the desired number of coats and divided by the industry-standard paint coverage rate of 350 sq ft per gallon.

Variáveis da Fórmula

Perimeter — Total distance around the room (2 × [Length + Width])

Gross Area — Total wall surface before window and door cutouts

Deductions — Subtracted surface for doors (20 sq ft) and windows (15 sq ft)

Coverage Rate — Standard yield of 1 gallon of quality paint (~350 sq ft / 32.5 m² per coat)

Premissas de Cálculo

One gallon of interior paint covers approximately 350 square feet (32.5 m²) on smooth, primed drywall.
Standard interior doors average 20 square feet (1.86 m²) and windows average 15 square feet (1.39 m²).
Unprimed, porous, or textured surfaces (like knockdown or popcorn) may require up to 20% more paint.

Trade FAQ

Perguntas Frequentes

Dúvidas comuns sobre reformas e materiaisCalculadora de Tinta

How many square feet does one gallon of paint cover?

A standard gallon of quality interior paint covers between 350 and 400 square feet with one coat on primed, smooth walls. On rough, textured, or unprimed drywall, coverage drops to 250–300 square feet per gallon.

Do I really need 2 coats of paint?

Yes. Even "paint and primer in one" formulas look significantly better with two coats. Two coats deliver uniform color saturation, eliminate roller streaks, and create a durable, washable paint film that lasts years longer.

How much paint do I need for a 12x12 room?

A standard 12x12 foot room with 8-foot ceilings, 1 door, and 1 window requires approximately 1.8 gallons for two coats on the walls. You should buy 2 full one-gallon cans.

Should I buy an extra quart or an entire extra gallon?

If your calculated need is slightly above a whole gallon (e.g. 2.1 gallons), buying 2 gallons plus 1 quart can save money. However, buying 3 whole gallons is often only slightly more expensive and ensures identical factory batch tinting and plenty of leftover paint for future scuffs.

How do I calculate paint for textured walls?

Heavily textured surfaces such as orange peel, knockdown, or stucco absorb more paint. Add 15% to 25% to your base square footage calculation to ensure complete coverage in all crevices.

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