All Roofings Calculator calculators

Pick the question you are trying to answer. Each calculator shows its formula, lists its assumptions and prints the arithmetic so you can check the result.

Shingles & materials

Bundles, starter, ridge cap, nails, underlayment, ice barrier, drip edge and flashing from one roof measurement.

  • Shingle Calculator

    Squares, bundles, ridge cap and nails for an asphalt shingle roof, from the roof area or the footprint and pitch.

  • Starter Strip Calculator

    Bundles of starter shingles for the eaves and rakes from the edge lengths and the coverage per bundle.

  • Hip & Ridge Cap Calculator

    Bundles and pieces of cap shingles for the ridge and every hip, at the exposure you choose.

  • Roofing Nails Calculator

    Nails, pounds and boxes for a shingle roof from the squares, the nailing pattern and the nail length.

  • Roof Underlayment Calculator

    Rolls of felt or synthetic underlayment and the cap nails to fasten them, with laps and waste counted.

  • Ice & Water Shield Calculator

    Rolls of self-adhering membrane for the eaves, valleys and penetrations, with the courses the code distance needs.

  • Drip Edge Calculator

    Pieces of drip edge for the eaves and rakes from the edge lengths, piece length and overlap, plus the nails.

  • Valley Flashing Calculator

    Valley metal pieces and lining rolls for open, closed-cut and woven valleys from the valley lengths.

  • Step & Wall Flashing Calculator

    Step flashing pieces for sidewalls and chimneys, kick-outs, counter flashing and whether a cricket is required.

Pitch & geometry

Pitch in any unit, true roof area from a footprint, rafter and hip lengths, truss counts, ridge height and ladder length.

  • Roof Pitch Calculator

    Pitch from rise and run, degrees or percent, with the pitch factor, hip factor and what the slope means for roofing.

  • Roof Area Calculator

    True roof surface area and squares from the building footprint, overhangs and pitch, with dormers and suggested waste.

  • Roof Pitch Factor Calculator

    The pitch factor and hip factor for any pitch, with a table of the common pitches and the area or rafter length they give.

  • Rafter Length Calculator

    Common rafter length from span or run and pitch, with ridge shortening, overhang, cut angles, birdsmouth and the board to buy.

  • Hip & Valley Rafter Calculator

    Hip or valley rafter length, run, plumb and cheek cuts, drop and the jack rafter difference for a regular hip.

  • Truss Count Calculator

    How many trusses a building needs at 12, 16, 19.2 or 24 in spacing, with gable-end trusses, lateral bracing and ties.

  • Gable Area Calculator

    The triangle area of a gable end from its width and pitch or peak height, for siding and sheathing, with rake trim length.

  • Ridge Height Calculator

    Rise and ridge height above the plate and above the floor or grade from span, pitch, wall height and rafter HAP, plus the fascia height.

  • Ladder Length Calculator

    The extension ladder size for an eave height using the 4:1 angle rule and the 3 ft extension, with the base distance from the wall.

Metal roofing

Panels, standing seam, screws, trim and cut lists for corrugated, ribbed and standing-seam roofs, and what they cost.

  • Metal Roof Panel Calculator

    Panels per side, panel length and total area for ribbed or corrugated metal roofing from the eave length, slope and coverage width.

  • Standing Seam Panel Calculator

    Standing seam panels, clips and screws from the eave length, seam spacing, slope and clip spacing, for snap-lock, mechanical and nail-strip systems.

  • Metal Roof Screws Calculator

    Panel screws, stitch screws and bags for an exposed-fastener metal roof from the squares or panels, the purlin spacing and the pattern.

  • Metal Roof Trim Calculator

    Ridge cap, eave, rake, valley and wall trim pieces, closure strips, butyl tape, sealant and trim screws from the edge lengths.

  • Corrugated Shed Roof Calculator

    Corrugated sheets, screws, ridge cap and foam closures for a gable or lean-to shed from its length, width and pitch.

  • Metal Panel Cut List

    Panel counts and lengths for up to four roof sections with their own run and pitch, grouped into order lines, cut to length or from stock.

  • Metal Roof Cost Calculator

    Installed cost range for an exposed-fastener, standing seam or metal shingle roof, with gauge, pitch, storeys, tear-off and region as separate lines.

Tile, slate & flat

Pieces per square for tile and slate, bundles of shakes, membrane rolls, rolled roofing and the battens under them.

  • Concrete & Clay Tile Calculator

    Field tiles, pallets, ridge and rake tiles and the dead load for concrete, clay, S-tile and barrel roofs.

  • Slate Roof Calculator

    Slates per square from slate size and headlap, total slates, copper nails and the weight of the roof.

  • Cedar Shake & Shingle Calculator

    Bundles of cedar shakes or shingles at your exposure from the Cedar Shake and Shingle Bureau coverage rules, plus hip and ridge.

  • Flat Roof Membrane Calculator

    Rolls of EPDM, TPO or PVC for a flat roof with turn-ups and seam laps, plus seam tape, adhesive and edge metal.

  • Rolled Roofing Calculator

    Rolls of mineral-surfaced roll roofing for exposed-nail, concealed-nail or double-coverage application, with nails and cement.

  • Synthetic Slate & Composite Shingle Calculator

    Pieces and bundles of synthetic slate or composite shake from piece width and exposure or the data sheet, with starter, ridge and weight.

  • Roof Battens Calculator

    Batten rows, linear feet, pieces and fasteners for a tile or slate roof from the slope length and gauge, with optional counter-battens.

Gutters & drainage

Gutter length, downspout count and size from roof area and rainfall, hangers, slope, guards and rain barrels.

Attic ventilation & insulation

Net free area by the 1:150 and 1:300 rules, ridge and soffit vents, box vents, attic fans, insulation depth and baffles.

  • Attic Ventilation Calculator

    Net free vent area by the 1:150 or 1:300 rule, split between soffit intake and ridge or roof exhaust.

  • Ridge Vent Calculator

    Feet of ridge vent, pieces and nails for the exhaust an attic needs, with the shortfall if the ridge is too short.

  • Soffit Vent Calculator

    Rectangular, round or strip soffit vents, or vented soffit panel, to deliver an attic's intake net free area.

  • Roof Box Vent Calculator

    How many box (low-profile) roof vents an attic needs for its exhaust and how to space them below the ridge.

  • Attic Insulation Calculator

    Inches and bags of blown fiberglass, cellulose or batts to reach the Energy Star R-value for your climate zone.

  • Attic Fan Sizing Calculator

    Powered attic fan CFM from attic volume and air changes or the 0.7 CFM rule, with the intake the fan needs.

  • Rafter Baffles Calculator

    Rafter vent baffles for every vented bay, and whether one reaches past the insulation at your depth and pitch.

Cost, tear-off & hiring

Replacement cost per square by material, labor, tear-off weight and dumpster size, repairs, DIY vs pro and an estimate builder.

  • Roof Replacement Cost Calculator

    Installed cost range for a new roof in any common material, with waste, pitch, storeys, tear-off, decking, region and permit as separate lines.

  • Roofing Labor Cost Calculator

    Crew hours and labor cost for a roof from the squares, material, pitch, storeys and tear-off, at a billed rate you set.

  • Tear-Off Weight & Dumpster Calculator

    The weight of an old roof by material and layers, the dumpster size and loads it needs and the disposal cost.

  • Roof Repair Cost Calculator

    Cost range for common roof repairs (shingles, pipe boots, flashing, chimneys, valleys, skylights, leaks) with access and region.

  • Roofing Cost per Square Calculator

    Turn a roofing quote into a price per square and per square foot, and see where it sits in the published range for its scope.

  • DIY vs Pro Roofing Calculator

    What doing a roof yourself really saves against a quote once materials, rentals, disposal and your hours are counted, with the safety caveats.

  • Roofing Time Calculator

    Worker-hours and days on site for a roof from squares, material, pitch, storeys, tear-off, crew size and a weather allowance.

  • Roofing Estimate Builder

    Build a roofing estimate from materials, tax, labor, disposal and permit, with overhead and profit as margin or markup made explicit.

Lifespan, planning & solar

Lifespan and cost per year, when to replace, weight on the structure, solar fit, project scheduling and skylight sizing.

  • Roof Lifespan & Cost per Year Calculator

    What a roof costs per year of life, with maintenance, compared with another material, from installed cost and expected life.

  • Roof Replacement Planner

    The expected replacement window for a roof from its install date, material, climate, ventilation and the warning signs you can see.

  • Roof Weight Calculator

    The dead load a roofing material puts on the structure, the change from the roof it replaces, and when an engineer should look.

  • Solar Panel Roof Fit Calculator

    How many solar panels fit on a roof face after fire-code setbacks, in portrait or landscape, and the system size in kW.

  • Roofing Project Schedule

    Finish date, book-by date and the order of work for a reroof from the start date, squares, material, crew and weather days.

  • Skylight Size Calculator

    How much skylight glazing a room needs by daylighting rule and which standard sizes fit between your rafters.