About Roof Geometry Lab

Roof Geometry Lab is a free set of roofing calculators built to be transparent about the math and honest about its limits.

The purpose of this site is narrow and practical: help homeowners, DIY builders and tradespeople get usable roof measurements before they order materials or check a quote. Every tool shows the formula it uses and a labeled diagram, so you can verify the result instead of trusting a black box.

The calculators run entirely in your browser. There is no account, no email gate and no server-side calculation. The geometry is derived from first principles and checked against a set of independent numeric fixtures described on the methodology page.

This is a planning tool, not an engineering or code-approval service. It does not provide structural sizing, cutting layouts or guaranteed purchase accuracy, and it does not claim professional review unless a named, qualified reviewer is actually credited here. Where a real operator, contact route or reviewer is configured, it will appear on the relevant page and nowhere else.