Roofing Calculators
Estimate all roofing materials from trusses and rafters to shingles and underlayment.
Free roof truss calculator — get truss count & spacing for any roof length. Enter span for 24" OC layout, cost estimate & design tips.
Free rafter calculator — get rafter length, count & spacing for any roof type. Covers 16" and 24" OC for gable, hip & shed roofs instantly.
Ridge board calculator: How many boards for my roof peak? Free tool for 2x8, 2x10 & 2x12 ridge boards — gives length and count.
How many OSB sheets to sheathe my roof? Free roof decking calculator for 4x8 panels — factors in roof pitch and waste percentage.
Free shingle calculator for roof shingles — get bundles, squares & cost from square feet. Covers 3-tab & architectural asphalt shingles.
How many rolls of roofing underlayment? Free calculator for 15 lb felt, 30 lb felt & synthetic — accounts for overlap and waste.
Drip edge calculator: Estimate linear feet of flashing for your roof. Free tool — gives piece count for standard 10 ft drip edge strips.
What pitch is my roof? Free roof pitch calculator — enter rise & run for instant angle, slope %, and area multiplier. Works for any roof type.
Free roof area calculator — convert flat dimensions to true roof area using pitch multiplier. Get roofing squares & material estimates.
Roof slope calculator — free tool to find pitch, angle, and sloped roof area multiplier. Enter rise & run for instant square footage results.
Free hip roof calculator — get rafter count, hip rafter length, roof area & ridge length. Covers common, hip & jack rafters for any building size.
Free gambrel (barn) roof calculator — get upper & lower rafter counts, roof area & wall height gained. Enter two pitches for instant results.
Free gable roof calculator — get rafter count, ridge length, roof area & gable end area. Enter building dimensions and pitch for instant estimate.
Free lean-to (shed) roof calculator — get rafter count, rafter length, roof area & rise height. Single-slope calculator for additions & sheds.