How to Calculate Roof Square Footage

Knowing the square footage of a roof is important for those home owners planning to replace the shingles on the roof. Even if a homeowner does not plan to do the work himself, knowing the square footage can help determine if an estimate from a roofing contractor is fair. Calculate square footage of a roof by using a simple calculator and a tape measure.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Tape measure Calculator

1. Measure the width and length of the rectangular areas of the roof. Some areas of the roof will contain both rectangular and triangular areas. Just measure the rectangular areas. Use the formula Length X width = square footage and record the results.

2. Measure the length and width of all triangular shaped sections of the roof. Use the formula 1/2( Base x Height ) = Area. Remember to divide by 144 to convert to square feet if all your measurements were in inches.

3. Add the results for all the rectangular and triangular areas of the roof to get the total square feet.

References

• Measuring your roof