Francesco Zinghinì
Author and curator of WindowCalcs.
Author and curator · WindowCalcs
Francesco Zinghinì is the author and curator of WindowCalcs. This is a truthful role: I am not a licensed window or door installer, a glazier, an architect or any trade professional, and I do not claim any such credential.
My relevant, verifiable competence is building deterministic online calculators (open-source Python projects) and electronic-engineering training (Systems Theory, Sapienza University of Rome) — which gives genuine rigor on the fenestration geometry and heat-transfer arithmetic. Window sizing is plane geometry (united inches = width + height; glass area = width × height ÷ 144; rough opening = unit size + shim gaps) and window energy performance is a steady-state conduction problem (R = 1 ÷ U; heating-season loss = area × U × HDD × 24; SHGC governs solar gain) — the same conductance/flow reasoning I apply in systems and electronics. Every formula on this site shows its basis, every convention is cited under Sources, and every calculator is numerically self-checked against known values (see Methodology).
Everything here follows one rule: the tools must stay correct with no ongoing maintenance. That is why every cost tool works only on the quantities you measure and the prices you enter from your own quotes and bills — the site keeps no material or labor price list, no regional cost database and no live rates that would silently go stale. The only baked-in numbers are stable identities (united inches = w + h, area = w × h ÷ 144, R = 1 ÷ U, 144 in² = 1 ft²) and clearly labeled published typicals (IRC R310 egress minimums, ENERGY STAR / IECC U/SHGC, standard shim gaps, U/SHGC by frame & glazing, cost bands) you can adjust to your own project.
Windows and doors are a real spend, so every cost tool is framed as a planning estimate, not a bid; every sizing tool reminds you to measure each opening (smallest of three) and confirm sizes, egress and energy ratings on the product and allow extra for custom sizes and waste; and the egress / energy / reference tools note their values are labeled typicals / code minimums, not a certified design — follow local code, the AHJ and the manufacturer’s NFRC data. The aim is a neutral, free, no-signup reference you can use to sanity-check an installer’s numbers — nothing that pretends to replace a professional install, an engineer or local code.
Elsewhere
Reach me through the contact page.