Free tool for anyone buying curtain fabric. It does what a simple area calculator misses: it rounds the fabric up to whole widths, keeps a pair even, and rounds each cut up to a whole pattern repeat, so the repeat waste is shown separately instead of hidden in the total.
Flat width = track width × fullness. Total widths = flat width ÷ fabric width, rounded up. For a pair, the total is rounded up to an even number, so both panels match. Raw cut length = drop + header allowance + hem allowance. If there is a pattern repeat, the cut length is rounded up to a whole number of repeats; the difference is the repeat waste per width. Total fabric = total widths × cut length. Plain lining uses the same widths but the raw cut length, because plain lining has no repeat to match.
Track 200 cm at 2 times fullness gives a flat width of 400 cm. At a fabric width of 140 cm that needs 3 widths, rounded up to 4 for a pair, or 2 per panel. Drop 240 cm plus 10 cm header and 10 cm hem gives a raw cut of 260 cm. On a 32 cm repeat, 260 cm rounds up to 288 cm, so 28 cm is wasted per width. Total fabric is 4 × 288 cm = 11.52 m (12.60 yd), including 1.12 m of repeat waste. Plain lining for the same widths is 4 × 260 cm = 10.40 m.
This is an estimate for planning and ordering, not a cutting instruction for a specific fabric. Check the fabric supplier's width, repeat and care instructions, and allow for seam allowances when joining widths and for any pattern direction or border that must stay upright. Measure the track, not the window, and measure the drop at both ends in case the floor is uneven.
Why does a pair need an even number of widths? So each panel gets the same number of widths and the pair hangs evenly. An odd total would leave one panel wider than the other.
What if my fabric is plain? Enter 0 for the pattern repeat. The cut length is then just drop plus header and hem, and the repeat waste is zero.
Why is the repeat waste shown separately? Because it is real fabric you pay for but do not see in the finished drop. Showing it separately stops a short order when the repeat is large.
Does this include lining? It shows plain lining separately, using the same widths and the raw cut length. If your lining has its own repeat, run it through the same calculation with that repeat.
About this tool: a free, single-page calculator. It runs entirely in your browser and does not save, upload or send your measurements. No sign-up and no payment are needed to use it.
Privacy: this page does not collect your measurements. Any advertising on this page, if approved, is served by Google AdSense; this page itself does not ask for your name, address or payment details.