How Many Square Feet in a Bundle of Shingles?

Before you start your project, you need to calculate the size of the roof you intend to cover. The square footage of a roof is normally measured in "squares" of 100 feet. Each square will need three bundles of shingles to cover it. Find the total square footage of your roof by multiplying the width by the length and then divide that number by 100 and you will get the number of squares you need to cover.
To find the amount of shingles you will need, multiply the number of squares by three. This number will be how many bundles of shingles you need to cover your roof, with a little left over for mistakes.