How to use this calculator
- Enter or choose frame width (outside).
- Enter or choose frame height (outside).
- Enter or choose profile face width.
- Enter or choose vertical mullions per window.
- Enter or choose horizontal transoms per window.
- The bars to buy updates as you type. Use Copy result or Share to keep it.
Method
Per window = 2W + 2H + Mullions × (H − 2f) + Transoms × (W − 2f); Bars by first-fit decreasing nesting of all cuts
- W, H
- outside frame size (mitred corners)
- f
- profile face width
Worked example
- Mullion = 1,500 − 2 × 60 = 1,380 mm.
- Per window = 2 × 1,200 + 2 × 1,500 + 1,380 = 6,780 mm; × 4 = 27.12 m.
- Nesting: 8 heights fill 2 bars, 4 mullions 1 bar, 8 widths 2 bars → 5 bars.
Four 1,200 × 1,500 mm windows with one mullion each need 27.12 m of profile, cut from 5 bars of 6 m.
What the result means
Profile systems often have separate frame, sash and bead profiles; run the calculator once for each profile type.
Assumptions and limits
- Outer frame members are cut to the full outside size with mitred corners.
- Mullions and transoms span the full inside of the frame; saw kerf is ignored.
- Where mullions and transoms cross, one of them is shorter in practice; the result slightly overstates length.
- Sashes, beads and glazing are not included.
Questions
What is the difference between a mullion and a transom?
A mullion is a vertical division; a transom is a horizontal one.
Why add a waste allowance on top of nesting?
For miscuts, damaged ends and trimming. The bar count already accounts for unusable offcuts.
Please note: Quantities are estimates. Confirm requirements with your engineer or supplier before ordering materials.