Home-exterior calculators
Free, no-signup calculators for homeowners, DIYers and contractors — roof pitch and area, shingle and material quantities, roof-replacement cost math on your own quotes, gutter sizing, siding quantities, window egress and energy, attic insulation and ventilation. Every tool shows its formula, a worked example and a reference table.
Roof Pitch & Geometry
Pitch from rise & run, pitch↔degrees, roof area from footprint, rafter length, ridge height and roofing squares.
All Roof Pitch & Geometry tools →Shingles & Materials
Shingle bundles, underlayment rolls, roofing nails, ridge-cap, drip-edge and metal-panel counts.
All Shingles & Materials tools →Roof Replacement Cost
Total from squares × YOUR price per square, quote converter, tear-off debris weight and two-material comparison.
All Roof Replacement Cost tools →Gutters & Drainage
Gutter length & downspout count, 5" vs 6" sizing from drainage area, downspout capacity, slope and cost.
All Gutters & Drainage tools →Siding & Exterior Walls
Siding squares from wall & gable area, vinyl panels from exposure, house wrap and siding cost.
All Siding & Exterior Walls tools →Windows
Replacement-cost worksheet, IRC egress opening check and U-factor energy-savings math on YOUR rates.
All Windows tools →Attic Insulation & Ventilation
Insulation depth for a target R, assembly R-value, blown-in bags, net-free vent area and heating savings.
All Attic Insulation & Ventilation tools →Roof Pitch & Geometry
Shingles & Materials
Roof Replacement Cost
Gutters & Drainage
Siding & Exterior Walls
Windows
Attic Insulation & Ventilation
Built for practice — and to stay correct forever
ExteriorCalcs gathers the calculations homeowners and contractors reach for when planning exterior work — the whole stack from roof geometry through materials, cost math, gutters, siding, windows and the attic — in one focused hub, in US units, without signup, with transparent formulas. Every tool shows not just the answer but the underlying formula, a worked example and a reference table.
Because the tools rest on timeless construction math (pitch multiplier = √(1+(rise/12)²), roof area = footprint × multiplier, drainage area vs gutter capacity, Q = A × HDD × 24 × Δ(1/R)) and stable industry/code constants (1 square = 100 sq ft, 3 bundles per square, SMACNA gutter capacities, IRC egress and ventilation minimums cited by edition, R-per-inch of insulation), they stay correct with no maintenance — no material prices, no labor database, no live feeds. Cost tools use the price you enter from your own quotes. More at Sources & formulas and About. Working on a roof is dangerous — measure from the ground where you can, use fall protection, and treat every result as a planning estimate, not a bid.