Wall Paint Calculator
Our wall paint calculator gives you the exact amount of paint needed for individual walls, not just a whole-room estimate. This is especially useful when you are painting a single accent wall, working with walls of different heights (such as stairwells or vaulted ceilings), or calculating square feet for painting a partial area.
Wall Measurements
Area: 96 sq ft
Area: 96 sq ft
Area: 96 sq ft
Area: 96 sq ft
Coats
Total wall area
384 sq ft
Paint needed
1.92 gallons
2 coats
Estimated Paint Required
1.92 gallons
4 walls · 2 coats
This calculator provides an estimate based on standard paint coverage rates. Actual coverage varies by surface texture, paint brand, and application method.
Our wall paint calculator gives you the exact amount of paint needed for individual walls, not just a whole-room estimate. This is especially useful when you are painting a single accent wall, working with walls of different heights (such as stairwells or vaulted ceilings), or calculating square feet for painting a partial area.
How to Use This Calculator
- 1.Enter the length (width) and height of each wall you plan to paint.
- 2.Add more walls as needed using the "Add Wall" button.
- 3.Set the number of coats (2 coats recommended).
- 4.The calculator sums the area of all walls and computes the total paint volume required.
Calculating Square Feet for Painting Walls
Each wall area is calculated as Length × Height. The calculator sums all wall areas to get the total paintable surface. Paint Volume = (Total Wall Area × Number of Coats) ÷ Coverage Rate. Standard interior paint covers approximately 400 sq ft per gallon (10 sq m per litre) on smooth surfaces. Textured or porous surfaces may reduce coverage to 300 sq ft per gallon (7.5 sq m per litre), so buy 10-15% extra if your walls are textured.
Frequently Asked Questions
How do I calculate square feet for painting a wall?
Measure the wall length and height in feet, then multiply: Wall Area (sq ft) = Length × Height. For example, a wall that is 12 feet wide and 8 feet tall has 96 sq ft. Repeat for each wall and sum the results for the total.
How much paint do I need for one accent wall?
For a 12×8 foot accent wall (96 sq ft) with 2 coats at 400 sq ft per gallon, you need 0.48 gallons — roughly half a gallon, or one quart with some leftover for touch-ups.
Should I subtract doors and windows from individual wall measurements?
If you are measuring each wall individually, you can subtract the area of any door or window on that wall before entering the dimensions, or simply measure the wall sections around them. This gives the most precise paintable area for each wall.
Does wall texture affect paint coverage?
Yes. Smooth walls typically allow 400 sq ft per gallon, while textured walls (orange peel, knockdown, or rough plaster) may only cover 300 sq ft per gallon. Buy 10-15% more paint for textured surfaces.
Last updated: 2026-10-06
Disclaimer: This calculator provides an estimate based on standard paint coverage rates. Actual coverage varies by surface texture, paint brand, application method, and environmental conditions. Always buy 10-15% extra paint for touch-ups and re-verify coverage rates on your paint can label.