Tie-Back Calculator — Curtain Tie-Backs

The proper method is to gather one curtain panel to its hung-back position and loop a tape measure around the bundle — that wrap distance is roughly your finished tie-back length. As a quick estimate this calculator uses 0.6 of the gathered stack circumference, which gives a snug pull on a typical pencil-pleat panel. For single-width panels tie-backs are usually at least 45 cm (18 in) finished; larger or heavier drapery often needs 60–75 cm (24–30 in). Heavy curtains need longer tie-backs; sheer curtains need shorter ones. Add a little extra if you plan to tie a knot or bow.

Standard positioning is roughly two-thirds down the curtain drop for a traditional look. At the halfway point for a formal look. Lower placement (three-quarters down) gives an elegant, elongating effect.

Use medium-weight fusible interfacing for standard tie-backs. For stiff crescent-shaped tie-backs, use heavyweight Vilene or buckram. For soft tie-backs, lightweight interfacing or none at all.

Use a cup hook, tie-back hook, or holdback mounted into the wall or window frame. For plaster walls, use wall plugs. Position the hook at the desired height and angle so the tie-back holds the curtain neatly.

Work it out from the cut size, not the area. Each strip is cut to (tie-back length + 2× seam allowance) long by (finished width + 2× seam allowance) wide. UK furnishing fabric is typically 137 cm (54 in) wide, so several short strips usually fit side-by-side across one width — this calculator nests them across the fabric width and sums the row lengths to give a true linear-metre figure. A single pair of small straight tie-backs often needs under one metre; allow a little extra for waste and pattern matching.