Reference tables
Look-up charts built from stable drainage geometry and labeled industry typicals — the gutter-size drainage-area matrix, roof-pitch area multipliers, US rainfall intensity by region, downspout capacity by size, installed cost per foot by material and by guard type, hanger / fastener spacing, and a K-style vs half-round capacity compare.
Typical published planning values — NOT a certified design. Actual gutter sizing depends on local rainfall intensity, roof geometry, valleys and debris; follow local code and the manufacturer’s data, and consult a pro for complex roofs. Structural roof-load, ice-dam / heat-cable and foundation/yard drainage are set by code and a professional — not engineered here.
Max roof drainage area per gutter size by rainfallThe signature reference: the max roof area each gutter size (5"/6"/7" K-style, 5"/6" half-round) drains at 2, 4, 6 and 8 in/hr — a neutral SMACNA-style drainage matrix.Roof-pitch area multiplier by pitchLabeled roof-pitch area multipliers = √(1+(rise/run)²) — the geometry behind the effective-roof-area and gutter-size tools.US rainfall intensity by region (in/hr)Labeled US 5-minute / 100-year rainfall-intensity bands by region — the input that sets how much roof a gutter size can drain.Max roof area per downspout by sizeLabeled max roof area each downspout size (2×3, 3×4, 3" and 4" round) carries — behind the downspout count tools.Installed gutter cost per linear foot by materialLabeled installed $/linear-foot bands by material (vinyl, aluminum, seamless aluminum, steel, copper, zinc) — a sanity guide behind the cost tools.Installed gutter guard cost per foot by typeLabeled installed $/linear-foot bands by guard type (screen, foam, brush, micro-mesh, reverse-curve) — a sanity guide behind the guard tools.Gutter hanger spacing, stock length & slopeLabeled hanger spacing (24–36 in), 10-ft stock length and 0.25–0.5 in/10 ft slope — the conventions behind the sections & slope tools.K-style vs half-round gutter capacity compareLabeled max roof drainage area at 6 in/hr for K-style vs half-round at 5" and 6" — behind the profile and 5-vs-6 compares.