How to Estimate the Amount of Shingles for a Hip Roof

Use the ladder to access the roof and eaves. Measure the length of the eave at the roof edge on the end of the house. Make a second measurement from the peak straight down to the roof edge. Multiply the eave length by the peak to eave distance and divide the result by two. The result is the area of one hip end.

For example: The eave at the end of the house is 28 feet long. The distance from the top of the peak on the hip end is 20 feet. 20 x 28 = 560. 560/2 = 280. The hip area is 280 square feet.

Measure the length of the central peak that runs from hip to hip, then measure from the central peak straight down to the eave in the front. Measure along the front eave from end to end. Multiply the central peak length by the peak to eave distance. The result is the rectangular section's area.

For example: The central eave length is 36 feet. The peak to eave distance is 18 feet. The rectangular section's area is 36 x 18 = 648 square feet.

Subtract central peak length from the front eave length and divide by two. Multiply the result by the peak to eave distance. The result is the area of the two triangular sections of the front roof. Since the two triangular sections are mirror images of each other, they form a rectangle when placed together and may be calculated as a single rectangle -- length x width.

For example: The eave length is 56 feet. 56 - 36 = 20 feet. 20/2 = 10 feet. The combined area of the two triangular sections = 10 x 18 = 180 square feet.

Add together the area of one hip end, the rectangular area of the front, and the triangular area of the front. Multiply the result by two to find the total roof area.

For example: Hip area + front rectangular section + front triangular section = 280 + 648 + 180 = 1108 square feet. Multiply by 2 to find the total area that includes the opposite hip end and the back of the roof. 1108 x 2 = 2216 square feet.

Multiply the total roof area by .05 and add the result to the total roof area. Divide the result by 100, and round up to the nearest whole number. The result is number of squares of shingles required to shingle the roof and accounts for waste and the cap shingles to use along the central and hip peaks.

For example: 2216 x .05 = 111. 2216 + 111 = 2327 square feet. 2327/100 = 23.27 rounded up = 24 squares of shingles for the hip roof.