Paint Calculator
Estimate paint for your walls and ceilings, with doors and windows taken out.
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How this calculator works
Add wall areas from each rectangular room: 2 × (length + width) × height. Subtract 21 sq ft per door and 15 sq ft per window. Optional ceilings use floor dimensions. Walls and ceiling paints are purchased separately, each applying coats, its coverage, and waste before rounding up whole gallons. Primer uses one coat across selected surfaces. Different-sized rooms share the chosen product/coverage assumptions.
Use current quotes, local rates, and measured dimensions to make this estimate useful for your situation.
Frequently asked questions
Can I estimate multiple rooms?+
Yes. Add rooms with their own dimensions, height, doors, and windows. Product coverage, coats, waste, and ceiling selection apply across the project.
Is primer included?+
Only when selected. Primer uses one coat and its own coverage and price. Ceiling paint is separately rounded; if using the same product everywhere, a combined purchase may use fewer gallons.