Paint Calculator
Choose the surface shape, enter dimensions, coats, and paint coverage to estimate total paint needed and number of cans to buy.
Calculer
Calculer
Measurements convert when you switch units
Résultat
La formule
Area is rectangle (L×W) or circle (π(d/2)²). Total coated area = area × coats. Paint needed = total coated area × (1 + waste%) ÷ coverage rate.
Exemple détaillé
- Room wall area 45 m², 2 coats → total coated area = 90 m²
- Coverage 10 m²/L with 10% waste → paint = 90 × 1.10 ÷ 10 = 9.9 L
- Using 2.5 L cans → cans = ceil(9.9 ÷ 2.5) = 4
Résultat: Order 9.9 L (4 cans of 2.5 L)
How paint quantity is calculated
The calculator converts your surface area and number of coats into total coated area, then applies waste and product coverage.
Coverage rate differs by surface
Rough plaster, old paint, or porous drywall can reduce real coverage compared with ideal label values.
Coats multiply consumption
If a color change or primer is needed, paint demand rises because each additional coat scales total area.
Order to full cans
Paint is purchased by can size. Rounding to full cans helps avoid under-ordering on installation day.
Faits intéressants
Manufacturer coverage is usually a lab estimate
Practical site conditions can produce lower spread rates than datasheet values.
Dark-to-light color changes may need extra coats
When hiding strong base colors, one additional finish coat is often required.
Primer can reduce finish-coat consumption
Appropriate priming improves substrate uniformity and can stabilize final coverage.
Texture increases paint demand
Textured walls and ceilings have greater surface area than flat surfaces of the same footprint.
Keep batch consistency for large jobs
Buying enough paint from the same batch helps reduce visible shade variation.
Temperature and humidity affect application
Drying conditions influence film build and may change practical consumption.
Questions fréquentes
It depends on product coverage, surface absorption, and coat count. This calculator combines those factors for a project-specific estimate.
Yes. Waste covers roller/tray losses, touch-ups, and small overages from real application conditions.
Many interior paints are around 8–12 m²/L per coat on smooth primed surfaces, but always use your product label.
Yes. Calculate each surface area and run separate estimates if products or coat counts differ.
Paint is sold in fixed can sizes, so partial cans must be rounded up to avoid running short.
Recommended. Primer and finish paints usually have different coverage and coat requirements.
Yes. Switch units to use ft² and gal-based coverage values.
For tighter estimates, subtract major non-painted openings from the input area.