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Exterior Paint Square Footage Formula:
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The exterior paint square footage calculation determines the total area that needs to be painted on the outside of a building. It accounts for wall height (in feet and inches), building perimeter, and subtracts areas not to be painted like windows and doors.
The calculator uses the following formula:
Where:
Explanation: The formula converts the height measurement to total feet (including inches as a fraction), multiplies by the perimeter to get total wall area, then subtracts window and door areas.
Details: Accurate square footage calculation ensures you purchase the right amount of paint, avoiding both waste and insufficient coverage. It also helps estimate project costs and time requirements.
Tips: Measure building perimeter carefully. For height, measure from base to eaves. For windows/doors, calculate each opening's area (width × height) and sum them. Round measurements to the nearest inch for best accuracy.
Q1: Should I include trim in the calculations?
A: Trim is typically included in the total wall area calculation. For precise estimates, you might calculate trim separately if using a different paint.
Q2: How much paint will I need?
A: Most paints cover 250-400 sq ft per gallon. Check your paint's coverage rate and divide total sq ft by that number.
Q3: What if my building has multiple heights?
A: Calculate each section separately with its own height measurement, then sum the results.
Q4: Should I account for texture or surface roughness?
A: Rough surfaces may require 10-20% more paint. Consider adding this to your total square footage.
Q5: How accurate should my measurements be?
A: For professional results, measure to the nearest inch. For rough estimates, rounding to the nearest foot may suffice.