Storefront Framing Calculator

This calculator takes off framing quantities for an aluminum storefront system: mullion counts, glass lite counts, door frames, total linear footage of framing, and an estimated system weight. Opening Width, together with Division Spacing, sets how many bays the storefront divides into, and that bay count is the basis for Vertical and Horizontal Mullions, Glass Lites, Total Framing, and Estimated Weight all at once -- at low door counts Opening Width tends to move Estimated Weight the most, but that ranking is not fixed: as Number of Doors climbs, Opening Height's effect on framing length and glass area can overtake it instead. Opening Height moves the vertical run of framing and the glass area within each bay, not how many bays or lites there are, since bay count comes from width and spacing alone -- but because that vertical run scales with every bay, Opening Height's pull on Estimated Weight grows as more bays become door openings. Number of Doors trims Vertical Mullions and Glass Lites, since a door opening replaces a mullion-and-lite bay, but only until that trimming floors out at zero; past that point Door Frames keeps climbing one-for-one and a fixed per-door weight allowance keeps accruing, so Estimated Weight can climb again even though no more bays remain to remove.

Door Height feeds the transom glass area above each door, so a taller door leaves less transom glass and can shift Estimated Weight noticeably. Door Width has its own field on the form, but no formula below reads it -- doors here are sized by count and height only, never by width, so filling in a different door width leaves every output unchanged. Always confirm header capacity for Estimated Weight against a licensed structural engineer's calculations before ordering material.