How Home Cost Compass estimates work
Our general project calculators turn an approximate project size into a low-to-high planning range, then adjust that range for market cost level, finish level, complexity, and the contingency you select. The midpoint is a planning reference—not a predicted contractor bid.
General cost calculator formula
planning range = project size × project rate × market × finish × complexity × contingency
Material, labor, permit, and contingency values are planning allocations intended to make quote conversations easier. Actual scopes and contractor pricing methods vary.
Roofing debris methodology
The specialist roofing tool estimates material weight, converts it into a loose-volume range, and compares both with general dumpster size and weight ranges.
| Material | Planning value |
|---|---|
| 3-tab asphalt shingles | 240 lb per roofing square |
| Architectural asphalt shingles | 420 lb per roofing square |
| Roofing felt/underlayment | 15 lb per roofing square when selected |
One roofing square covers 100 square feet. The shingle values follow GAF's general tear-off guidance.
Roofing formula
roofing squares = roof area in square feet ÷ 100
base weight = squares × shingle weight per square × layers + selected extras
expected weight = base weight × (1 + planning allowance)
Limitations
- Use actual project measurements where possible.
- Local labor, access, materials, permits, and hidden conditions can materially change cost.
- Tile, slate, metal, built-up roofing, and commercial membrane systems are not supported by the debris tool.
- Local codes, landfill rules, permits, truck limits, and rental contracts override these estimates.
Sources
Last methodology review: July 2026.