How do I determine my wall's surface area?

Accurately calculating your wall surface area is an essential first step before starting any painting project. It helps you determine how much paint you’ll need and ensures a smooth, efficient workflow without unnecessary trips back to the store.

The process is straightforward and can be done with just a tape measure:

• Measure the width of each wall from side to side
• Measure the height from the baseboard up to the ceiling
• Multiply the width by the height to get the surface area of that wall

Repeat this process for every wall in the space, then add all the individual wall areas together to get your total paintable surface area.

For a more precise estimate - especially in rooms with multiple openings - you can subtract the areas of doors and windows. While this step is optional, it can help fine-tune your calculations and prevent over-purchasing paint.

Once you have your total square footage, you can estimate how much paint you’ll need. As a general guideline, most Benjamin Moore interior paints such as Regal Select or AURA cover approximately 350-400 square feet per gallon, depending on the surface texture and porosity.

Keep in mind that highly porous surfaces, drastic colour changes, or applying multiple coats may require additional paint. Pairing your topcoat with a quality primer like Benjamin Moore Fresh Start can also improve coverage and reduce the number of finish coats needed.

Summary: Measure each wall’s width and height, multiply to get individual areas, then add them together for the total. Subtract doors and windows for a more accurate estimate, and use that number to determine how much paint you’ll need for a professional result.