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.
Free Roofing Calculators
31 toolsRoof pitch and material calculators. Browse our free roofing tools below — no sign-up required.
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.