calcs.homes
calcs.homes
Enter your roof area and this shingle calculator gives you the number of roofing squares, the bundles of shingles to buy (most run 3 bundles per square), and an estimated material cost.
Estimate only — hip, ridge, and starter courses use extra bundles not counted in the field total.
We convert roof area to squares (100 sq ft each), add your waste allowance for cut-off and breakage, then multiply by bundles per square — three for most architectural and three-tab shingles. The bundle count rounds up because you cannot buy a partial bundle, and cost multiplies whole bundles by your price.
Ten percent waste suits a simple roof; use 15% or more for a roof with many hips and valleys, where every course is cut on an angle. Ridge caps, starter strip, and hip shingles are sold separately or cut from field bundles, so add a few bundles for those if you are not buying dedicated accessory products.
Three bundles per square is standard for architectural and most 3-tab shingles. Heavier designer shingles can run four or five bundles per square — check the wrapper.
About 10% for a plain gable roof, and 15–20% for a complex roof with lots of hips, valleys, and dormers where shingles must be cut on angles.
Yes. Ridge caps and starter courses are extra — budget one bundle of cap shingles per 30–35 linear feet of ridge and hip, plus starter strip for every eave and rake.