Paint Calculator
Estimate how much paint you need for walls and ceilings.
About This Tool
When to Use This Calculator
Use the Paint Calculator before purchasing paint for any interior or exterior project — walls, ceilings, accent walls, or full room makeovers. Buying the right amount of paint avoids waste and ensures color consistency across the entire job, since paint colors can vary slightly between production batches even with the same formula code.
How It Works
Enter room dimensions and the calculator computes total paintable surface area, subtracting standard deductions for doors, windows, and other openings you specify. It factors in the coverage rate per gallon (typically 350–400 square feet for most interior latex paint), the number of coats you plan to apply, and tells you exactly how many gallons to purchase.
Tips for Best Results
- Most color changes require two coats minimum. Going from a dark color to a light one? Budget for a coat of primer plus two top coats to avoid bleed-through.
- Textured surfaces like stucco, popcorn ceilings, or heavy knockdown texture use 20–30% more paint than smooth surfaces due to the extra surface area in the texture.
- Always buy a little extra for future touch-ups — matching a dried, aged paint color years later is nearly impossible, even with the original formula.
- Ceiling paint typically has a flatter sheen and thicker consistency than wall paint. Calculate ceilings separately if using a different product.