Windows & Doors
Calculators.
Free precision tools — no signup, no ads.
5 Tools
Window Energy Calculator
Calculate annual heat loss cost through windows by U-value — compare single, double, and triple pane with ENERGY STAR compliance check
Window U-Factor Calculator
Compare window U-factors to calculate annual heat loss reduction, energy savings, and payback period for window replacements
Door Rough Opening Calculator
Calculate door rough opening dimensions for prehung, sliding, bifold, and pocket doors — with header sizing and framing member list
Door Sizing Calculator
Calculate door rough opening dimensions, header size, ADA compliance clearances, and framing materials for any door size and type
Weatherstripping Calculator
Calculate weatherstripping length needed, air leakage reduction, and annual energy savings for doors and windows by gap size and strip type