Garage Door Opening Calculator
Calculate preliminary garage-door rough-opening dimensions, total opening area, perimeter trim, stock pieces and entered unit cost.
Default project preview
9 × 7 ft
Total opening area
126 ft²
Three-side trim
46 ft
Trim stock pieces
5
Side allowance
0 in
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Rough width = nominal width + two side allowances. Rough height = nominal height + top allowance. Trim follows two sides plus the head.
FAQ
Garage Door Opening Calculator questions
Should the rough opening equal the door size?+
Many systems use specific opening dimensions, but requirements vary. Follow the exact door manufacturer instructions.
Does this calculate headroom and backroom?+
No. Track type, opener and hardware determine required clearances inside the garage.
Does it size the structural header?+
No. Header design depends on span, loads, wall construction and local requirements.