About Window Fabrication Calculator
The window fabrication calculator turns window dimensions and a glazing specification into a complete production package: cutting lists for the frame, sash, and mullion profiles, glass and hardware schedules, an optimized stock-bar cutting plan, and a costed quotation. It is built for aluminum and PVC window manufacturers, fabricators, and contractors.
Set the window width, height, type, and panel count, choose the glazing and profiles, and enter your labor rate, overhead, discount, and tax. The tool returns the cut pieces with miter angles, the glass sizes, the cutting efficiency, and a full materials, labor, overhead, and tax cost breakdown.
How It Works
- Deduct the frame profile width from the window dimensions to derive the frame, sash, and mullion cut lengths and the glass sizes.
- Lay out the cut pieces onto standard stock bars with a First Fit Decreasing algorithm, accounting for the saw blade kerf and reusable offcuts.
- Cost the profiles per metre, the glass per square metre, and the hardware and seals per unit, then add labor based on window type, panels, and area.
- Apply overhead, discount, and tax to the subtotal to produce the final quoted total.
Worked Example
A 1200 x 1500 mm fixed window: profiles 30.00, single glazing (0.8 m2 at 25/m2) 20.00, handle 20.00 plus 3 m seal at 3/m = 9.00, giving materials of 79.00. Labor is 2.0 h at 50/h = 100.00. Overhead 10% of (79 + 100) = 17.90, subtotal 196.90. After a 5% discount (-9.85) the net is 187.05, and 17% tax adds 31.80 for a total of 218.85.
Formulas
- Frame cut deduction
frameDeduction = frameWidth * 2- Window area (for labor)
area = (width * height) / 1000000- Cutting utilization
utilization = (usedLength / stockLength) * 100- Labor cost
laborCost = hours * laborRate- Quoted total
total = (subtotal - discount) * (1 + taxRate / 100)
Standards & References
- 6000 mm standard stock length
- 5 mm saw kerf
- 300 mm minimum reusable offcut
Frequently Asked Questions
What window types does the calculator support?
It supports fixed, sliding, casement, awning, and hopper windows, with one to six panels. The window type sets the sash configuration and a labor multiplier for the cost estimate.
How does the cutting optimization work?
Cut pieces are packed onto standard 6000 mm stock bars using a First Fit Decreasing algorithm that accounts for the 5 mm saw kerf per cut and flags offcuts of 300 mm or more as reusable, reporting the overall material utilization.
What is included in the cost breakdown?
The cost covers profiles (per metre), glass (per square metre), hardware and seals (per unit/metre), and labor (hours times rate), then applies overhead (percentage or flat), a discount, and tax to give the final total.
How are glass sizes determined?
Glass width and height are derived from the panel size minus the frame and sash channel depths and an edge clearance, so the cut glass fits the rebate with the required tolerance.