ABOUT ROOFLINE

A clearer starting point for your roof plan.

Roofline is a free set of calculators and guides for roof area, pitch and material quantities. It is for homeowners and project planners who want to understand the geometry behind an estimate before they talk to a supplier or a contractor.

Who operates the site

Roofline is built and published by Schiesser IT, LLC. We are software developers, not roofers, engineers or building officials. That shapes what the site does: it computes geometry exactly, shows the formula, names its sources, and leaves judgments about your particular roof to the people who can inspect it.

info@schiesser-it.com · Contact and corrections

How results are calculated

Every figure comes from a small set of formulas that are printed on the calculator pages:

• Roof footprint = (length + 2 × overhang) × (width + 2 × overhang), from building dimensions at the outside walls.
• Area multiplier = √(1 + (pitch ÷ 12)²). Roof area = footprint × multiplier.
• Angle = arctan(pitch ÷ 12). Slope percentage = pitch ÷ 12 × 100.
• Order area = roof area × (1 + waste ÷ 100). Roofing squares = order area ÷ 100.
• Packages = order area or length ÷ the coverage you enter, rounded up to a whole package.

Ridge, hip and edge lengths are derived from the same section geometry. For a rectangular hip roof with equal pitch on all faces the ridge is the difference between roof length and width, and each hip is the diagonal from a corner up to the ridge end. The calculators work in feet internally and convert for metric display.

How results are checked

The calculation code is one module used by all three calculators and by every table in the guides, so a number in a guide cannot drift away from what the calculator shows. That module has automated tests against cases worked by hand: the default 40 × 30 ft gable roof, pitch conversions including 12:12 = 45°, a hip roof whose hips can be verified with the Pythagorean theorem, package rounding and the input limits. Running them is part of our checklist before a change is published.

What the tests cannot check is whether the model fits your roof. The calculators assume rectangular sections with a single pitch and the same overhang on every side. Valleys, dormers, shared edges and multi-pitch faces need manual adjustment, and the pages say so where it matters.

Where the guides get their figures

Geometry is computed. Anything that is not geometry, such as a minimum slope in a building code or the coverage of a product, is quoted from a source we have read and is linked at the end of the guide: adopted code text, municipal permit documents, manufacturer data sheets and trade publications. Product figures are examples of how packaging works, not recommendations. If we cannot find a source for a figure, we leave it out. We do not publish price estimates.

There are 8 guides at present. Each shows the date it was last updated.

How to report an error

Send the calculator or guide, your inputs and what you expected to info@schiesser-it.com. The contact page lists what helps us reproduce a result. Corrections are made on the page and dated.

What Roofline does not do

• It does not replace a measurement on the roof, a structural assessment or a contractor’s quotation.
• It does not tell you what your local building code requires. Codes are adopted and amended by states and municipalities.
• It does not recommend contractors, products or brands, and it has no affiliate links.
• It does not store your measurements on a server. They stay in your browser tab; see the privacy information.

How the site is funded

Roofline is free to use. It does not currently show advertising. We intend to fund it with advertising and will say so here when that starts.

Change history

• October 28, 2026Added loadable worked examples with replacement confirmation, a calculation breakdown for every section, and a printable ledger of dimensions, areas and product assumptions. Corrected the formula display when metric units are selected.
• October 13, 2026Analytics now runs by default for visitors outside the EEA, UK and Switzerland, with an opt-out under Privacy settings. Visitors in those regions are still asked first.
• October 12, 2026Added the homepage, eight guides, a contact page and terms of use. Material quantities and guide tables now run on one shared calculation module with automated reference tests.
• October 9, 2026Moved hosting to Cloudflare and fixed the start of consent-based analytics.
• October 3, 2026Redrew the shed roof icon in the shape selector, which had crossing edges.
• September 29, 2026Added Google’s certified consent message for visitors in the EEA, UK and Switzerland and updated the privacy information.
• September 27, 2026Published the formula, worked-example and reference sections on the three calculators.

Start here

• Roof area calculator: Footprint, overhang and pitch to sloped roof area and roofing squares, for one or several roof sections.
• Roof pitch calculator: Rise and run to pitch, angle in degrees, slope percentage and the area multiplier.
• Roofing material calculator: Shingle bundles, underlayment rolls, ridge and hip caps and drip edge from your own package coverage.
• Roofing guides: measuring, pitch, squares, waste, accessories and metal panels.