Curtain fabric calculator
This curtain fabric calculator works from rail width, drop and fullness: for a 2 m rail and a 2.50 m drop at double fullness you need 4 widths and 10.84 m of fabric.
Source: Wikipedia – Vorhang (Raffung, Faltenbildung, Aufbau). Updated: .
How it is calculated
The fabric width needed is rail width times the fullness factor, plus allowances for the side hems. For a 200 cm rail at double fullness that is 400 cm, and with 3 cm side allowance per edge on two panels 412 cm.
How it is calculated
The total width is split between the panels and divided by the fabric width, rounded up to whole widths. The cut length per width is the finished drop plus the allowance for the bottom hem and the allowance for the heading. For patterned fabrics the length is rounded up to a multiple of the pattern repeat so the pattern runs across the seams. Metres of fabric are widths times cut length.
Fullness and fabric choice
The fuller the folds, the more fabric: lightly gathered is about 1.5 times the rail width, wave fold and similar tapes 2 times, gathered tape up to 2.5 times, very full pleats 3 times. Light, flowing fabrics take more fullness than stiff ones.
- Fabric widths of 140 cm are common; sheer fabrics often come 280 cm wide, which removes the seams.
- For blackout or lining, calculate the quantity again.
- The calculation also works for tablecloths, bed skirts and room dividers.
Frequently asked questions
How much fabric do I need for a curtain?
Rail width times the fullness factor, divided by the fabric width, gives the widths; times the cut length gives the metres. For a 2 m rail and 2.50 m drop that is about 11 m.
What fullness factor is usual?
Mostly 2 times the rail width. Light fabric can go up to 2.5 times, and 3 times for a very full look.
How do I calculate patterned fabric?
Enter the pattern repeat in cm. The cut length is rounded up to a multiple so the pattern matches at the seams.
Sources and legal basis
- Wikipedia – Vorhang (Raffung, Faltenbildung, Aufbau)
- Wikipedia – Gardine (Gardinenarten, Verarbeitung)
- Wikipedia – Rapport (Textil) – Musterwiederholung
As of: · Editorial policy
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