Roofing & Exterior Calculators
Free roofing and exterior calculators for shingle bundles, roof squares, and paint quantities. Plan material purchases with clear estimates.
Roofing & Exterior estimating tools
Planning a roofing & exterior material estimate
Roofing estimates must use sloped surface area, not only the building footprint. Pitch multipliers can convert a simple horizontal footprint, but hips, valleys, dormers, intersecting roofs, and varying eaves are more reliable when measured as separate planes.
One roofing square equals 100 square feet of roof surface. The number of shingle bundles per square depends on the exact product: many standard products use three, while heavier premium products can require four, five, or six. Underlayment, flashing, starter, ridge material, ventilation, and fasteners are separate takeoffs.
Check before calculating
- ✓Include eaves and overhangs in the measured roof outline.
- ✓Confirm pitch for every plane rather than assuming the whole roof matches.
- ✓Read the wrapper or data sheet for bundles per square and exposure.
- ✓Increase planning allowance for valleys, hips, dormers, and small planes.
- ✓Use safe remote measurement or a qualified roofer; do not access an unsafe roof.
A reliable workflow
- 1Create a plane-by-plane roof sketch.
- 2Calculate sloped area and total roofing squares.
- 3Apply a layout-specific cutting allowance.
- 4Convert squares to bundles using the selected product.
- 5Obtain a separate accessory and flashing takeoff before ordering.
Common questions
Are there always three bundles in a roofing square?
No. Three is common for many products, but bundle coverage varies. Use the manufacturer’s current bundles-per-square value for the exact shingle.
Does the shingle estimate include underlayment and ridge caps?
No. Those components have different coverage rules and should be calculated separately from field shingles.
For measurement and ordering help, use the BuilderCal planning guides. For site-wide calculation standards, see our methodology.