Free Online Curtain Size Calculator
Calculate curtain fabric, fullness, and panel requirements.
Pencil and pinch pleats usually need 2–2.5×; eyelets around 1.8–2×; tab tops 1.5–1.8×.
Details
This is an estimate for a pair of curtains. A very wide window may need more than two hanging panels; the fabric widths figure shows how many fabric drops are required. Check the fabric's usable width, because the selvedge is often trimmed before sewing.
About the Curtain Size Calculator
Curtain fabric is usually sold by the meter, but curtains are made from vertical drops cut to the finished length. The amount you need depends on the window width, the fullness you want, the width of the fabric, and the pattern repeat. This calculator works through those factors and reports the number of fabric widths, the cut length for each drop, and the total fabric in both meters and yards. A lining estimate is included when you enable it.
Fullness and header type
Fullness is the ratio of gathered fabric width to the window width. A 2× fullness means the curtains use twice the window width before pleating or gathering. Pencil pleat and pinch pleat headings usually look best around 2.2× to 2.5×, eyelet headings around 1.8× to 2×, and tab tops around 1.5× to 1.8×. Wave or ripplefold headings need a consistent 2× to 2.2× depending on the track. More fullness creates deeper folds and a richer look, but it also adds fabric, weight, and cost.
Cut length and pattern repeat
The finished drop is not the cut length. Extra fabric is needed for the header, the bottom hem, and pattern matching. This calculator adds a header allowance based on the type you choose plus a bottom hem, then rounds the result up to the next full pattern repeat when a repeat is entered. That rounding is why two fabrics with the same drop can require different amounts of cloth. Always add a little extra for squaring the fabric and for future alterations.
Panels, widths, and lining
A typical window is dressed with a pair of curtains, one on each side. Each panel may be wider than a single fabric width, so a wide window needs several drops joined together. The tool reports the total number of fabric widths and assumes the drops are split evenly between two hanging panels. Lining is cut from the same drop lengths and is shown as the same quantity, though a maker may trim it slightly shorter. Heavier interlining and blackout lining add thickness, so discuss the heading with your maker before ordering.
Frequently asked questions
Should I measure the window or the curtain track?
Measure the track or pole width, not the glass. Curtains usually extend beyond the window so they can close without light gaps and stack clear of the glass when open. For a track, measure the full track length; for a pole, measure between the finials.
Why does the drop need extra length?
The header needs fabric to form pleats or eyelets, the bottom needs a hem, and patterned fabric needs matching at the seams. The finished drop is measured from the track or pole to the floor or sill, after those allowances are taken out.
Are the results in meters or yards?
The fabric total is shown in both meters and yards. The input unit selector controls the window, drop, fabric width, and pattern repeat fields, so keep all of those in the same unit. The conversion between units is automatic when you switch the selector.