Curtain Fabric Window Width cm
Estimates curtain fabric centimeters from window width and desired pleat ratio.
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Estimating Curtain Fabric and Fullness
This calculator works out the fabric a curtain needs from three things: the window width, a fullness factor and the drop you want. The formula is fabric (cm) = ceil(width × fullness + height). Why multiply the width by the fullness ratio? Because a curtain gathers or pleats rather than hanging flat, so the panel has to be wider than the window to ripple and drape properly. The drop gets added afterward to cover the vertical length along with hems and headers.
Fullness is what really drives this calculation. Roughly speaking, 2× gives you a light, casual gather. 2.5× is the usual go-to for medium-weight fabric, while 3× delivers that rich, full look people like for sheers and formal pleated headings. As a rule, lighter fabrics can take more fullness than the heavy ones.
Applications
Handy for interior decorators, curtain makers and homeowners pricing out window treatments, and for working out how many widths of fabric to buy before sewing pinch-pleat, pencil-pleat or eyelet curtains.
FAQ
What fullness should I pick? Go with 2× for a relaxed look, 2.5× when you want a safe default, and 3× for sheers or really lush gathers.
Does this account for pattern repeats? No. If you have a patterned fabric that has to line up across panels, you'll need extra cloth. For large repeats, add one repeat length per drop.
Should I add for hems? The height term already builds in some allowance, but it's worth a few extra centimetres for deep bottom hems and headers, just to be safe.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.