Estimate how many squares of siding or cladding, starter strips, and trim you need for your project.
Step 1: Calculate your total wall area (length × height for each wall, added together).
Step 2: Measure and enter the total area of all openings (windows and doors).
Step 3: Add any gable area if your siding extends into the gable.
Step 4: Select your siding type and adjust the waste percentage (10% is standard, 15% for complex layouts).
Results are given in "squares" (1 square = 100 sq ft / 9.29 sq m) which is the standard ordering unit.
A square is a unit of measurement equal to 100 square feet (9.29 sq m) of coverage. Siding is typically sold and priced per square.
10% waste is standard for simple rectangular walls. Add 15% for walls with many windows, dormers, or irregular shapes. Diagonal installations may need 20%.
Gable area = (base × height) / 2. Measure the width at the base and the height from the top of the wall to the ridge peak.