How the math works
A roofing square is 100 square feet of roof surface. Pitch adds area: a 4/12 roof has about 5.4% more surface than its footprint, an 8/12 roof about 20% more. Waste covers cutting at hips, valleys and edges. Hip roofs, which are common in Southern Nevada, usually need more waste than simple gables.
Why tile counts matter
On a tile roof, the number of broken or displaced tiles helps frame the repair-or-replace question. If breakage is scattered across many slopes, lifting and resetting courses to replace individual tiles can approach the cost of a full re-roof, especially when the underlayment is aged.
Limits
Real roofs have dormers, multiple pitches and complex intersections. Use the calculator for a sanity check, not a bid. Tiles per square varies by manufacturer and profile.
All example figures are illustrative.
Questions about this tool
My estimate shows fewer squares than this calculator. Why?
The estimate may have measured a different area, used a lower pitch or omitted waste. Ask how it was measured.
Does pitch change the price?
Steeper roofs often carry steep-roof labor charges in estimating software, typically starting around 7/12 or 8/12.