Glass Thickness Calculator

This calculator estimates the minimum glass thickness a panel needs to withstand a given wind load, based on design wind speed, panel dimensions, elevation, and glass type. Glass Type has a bigger effect on Minimum Thickness than a realistic change in Design Wind Speed does: the allowable stress this calculator uses runs from 1,000 psi for Annealed glass up to 4,000 psi for Tempered -- four times stronger -- so switching from Annealed to Tempered on the same panel and wind load cuts the required thickness roughly in half. Design Wind Speed still matters, since wind pressure scales with the square of speed, and Minimum Thickness rises with the square root of that pressure.

Only the shorter of Panel Width and Panel Height governs Minimum Thickness -- with a 36-inch by 60-inch panel, Panel Height can change substantially without moving the result at all, because the formula always uses the shorter side. Elevation reduces wind pressure slightly as it increases, reflecting thinner air at altitude, though its effect at typical elevations is small compared to wind speed or glass type. Breakage Probability and Safety Factor are simplified estimates meant to flag a design that's cutting it close, not a substitute for a licensed structural engineer's sign-off.