Quick answer
Coverage varies by paint, substrate, texture, porosity, color change and application method. Use the manufacturer’s coverage range for the exact product, then plan conservatively for rough or porous surfaces.
Step by step
- Choose the actual paint. Find the product coverage specification.
- Inspect the surface. Rough or porous surfaces can reduce coverage.
- Set coat count. Primer and finish coats should be planned separately when products differ.
- Calculate and round. Divide total coverage area by product coverage and round to available can sizes.
Formula or rule of thumb
Example
If two coats create 700 coverage ft² and the paint is rated at 350 ft²/gal, the theoretical need is 2 gallons before real-world allowance and can-size rounding.
Common mistakes
Do not assume every paint covers 400 ft² per gallon. Product specifications and surface conditions can materially change the result.
Planning note: product yields, installation methods, site conditions and local requirements can change the final quantity. Use the exact manufacturer or supplier information before purchasing.
FAQ
Why does textured wall use more paint?
Texture increases surface area and can hold more coating in recesses.
Does primer count as paint coverage?
Primer should usually be estimated using its own coverage rate because it is a different product.
Can color change affect coats?
Yes. Strong color changes can require primer or additional finish coats depending on the paint system.