Roof pitch and material calculators. Browse our free roofing tools below — all calculators are instant, accurate, and require no sign-up.
Attic Ventilation Calculator — Calculate required attic ventilation NFA using the 1/150 or 1/300 rule. Determines total, intake, and exhaust net free area for proper attic airflow.
Built-Up Roofing (BUR) Calculator — Estimate built-up roofing materials: felt plies, asphalt flood coats, gravel ballast, and base sheet for multi-ply BUR flat roof systems.
Dormer Material Calculator — Estimate materials for a dormer: roof area, side wall area, face wall area, and window opening. Calculate shingles, siding, and flashing needs.
Drip Edge Calculator — Calculate drip edge flashing needed for eave and rake edges. Estimates pieces, linear feet, and total cost for metal drip edge roofing material.
Dutch Gable Roof Area Calculator — Calculate Dutch gable (Dutch hip) roof area combining hip slopes with gable triangles at each end. Estimate roofing materials accurately.
Flat Roof Area Calculator — Calculate flat roof area including parapet walls and overlap allowances. Estimate TPO, EPDM, or built-up roofing membrane quantities accurately.
Gable Roof Area Calculator — Calculate the total area of a gable roof using building length, width, and roof pitch. Estimate materials for shingles, underlayment, and more.
Gambrel Roof Area Calculator — Calculate gambrel (barn-style) roof area with upper and lower slope panels on two sides. Estimate shingles and materials for this classic double-pitch design.
Hip Roof Area Calculator — Calculate the total surface area of a hip roof from building dimensions and pitch. Estimate shingles, underlayment, and ridge cap materials.
Ice & Water Shield Calculator — Calculate ice and water shield membrane needed for eaves, valleys, and penetrations. Estimates linear feet and rolls for cold-climate roof protection.
Mansard Roof Area Calculator — Calculate mansard roof area with upper and lower slope panels on all four sides. Estimate shingle and slate quantities for this classic double-slope design.
Metal Roofing Panel Calculator — Calculate the number of metal roofing panels needed based on roof width, panel coverage, and eave-to-ridge length. Includes trim and fastener estimates.
Ridge Vent Length Calculator — Calculate ridge vent length needed for your roof. Determines net free area, ridge vent linear feet, and compliance with exhaust ventilation requirements.
Roof Flashing Calculator — Calculate step flashing, counter flashing, and pipe boot quantities for roof-to-wall intersections, chimneys, and pipe penetrations.
Roof Pitch Angle Calculator — Convert roof pitch X:12 notation to degrees, percentage slope, and radians. Quick reference for roofers, framers, and building inspectors.
Roof Pitch Calculator — Calculate roof pitch from rise and run measurements. Convert between pitch ratio, degrees, and percentage slope for roofing material selection.
Roof Slope Factor Calculator — Calculate the roof slope factor (multiplier) from pitch. Multiply footprint area by this factor to get true sloped roof area for any pitch.
Roof Truss Spacing Calculator — Calculate the number of roof trusses needed based on building length and truss spacing. Includes total truss count and gable-end truss requirements.
Roof Underlayment Calculator — Calculate how many rolls of roof underlayment you need. Accounts for coverage per roll, overlap loss, and waste for felt or synthetic underlayment.
Roofing Squares Calculator — Convert roof area to roofing squares and calculate bundles needed. One roofing square equals 100 sq ft. Essential for ordering shingles and materials.
Shed Roof Area Calculator — Calculate the surface area of a single-slope shed roof from length, width, and pitch. Estimate roofing materials with waste factor included.
Shingle Bundle Calculator — Calculate shingle bundles needed from roof area and coverage per bundle. Accounts for different brands with varying coverage rates per bundle.
Shingle Quantity Calculator — Calculate the number of shingle bundles needed for your roof. Supports 3-tab, architectural, and designer shingles with waste factor included.
Skylight Flashing Calculator — Estimate skylight flashing kit requirements based on skylight dimensions and roof pitch. Includes step flashing, head/sill flashing, and ice shield.
Slate Roofing Quantity Calculator — Calculate slate roofing quantity from roof area, slate dimensions, and exposure. Estimate total slates needed for natural or synthetic slate installations.
Soffit Panel Calculator — Calculate soffit panels needed for eave enclosure. Estimates panel count from soffit area, panel dimensions, and optional vented panel requirements.
Soffit Vent Calculator — Calculate the number of soffit vents needed for proper attic intake ventilation. Determines vent count from required NFA and individual vent NFA rating.
Standing Seam Roofing Calculator — Calculate standing seam metal roofing panels, clips, and trim needed. Accounts for panel width, seam overlap, eave-to-ridge length, and accessories.
Tile Roofing Count Calculator — Calculate how many roof tiles you need based on roof area and tile coverage. Supports clay, concrete, and flat tile types with waste factor.
TPO / EPDM Membrane Calculator — Calculate TPO or EPDM single-ply membrane roofing material needed. Accounts for field area, parapet wrap, seam overlaps, and adhesive requirements.
Valley Flashing Calculator — Calculate valley flashing material needed for open and closed roof valleys. Estimates linear feet of W-valley metal and ice/water shield underlayment.