A drapery pleat calculator determines exact spacing, pleat size, and fabric consumption for custom curtain panels. Enter the flat fabric width you have after side hems, the finished width you want, the hardware return and center overlap, and how many pleats to divide the panel into. It returns the fabric each pleat swallows and the flat space between them, with a virtual tape measure showing where every pin goes.
Panel Specifications
Pleat Architecture
📏 Virtual Tape Measure
SVG visualization of exact pin placement positions on your flat fabric panel.
Enter your specs and hit Architect to see the tape.
Drapery Architecture Gear
Perfect pleat math is only half the battle; you must secure those pleats so they hold their structure when hung. We strongly recommend using heavy-duty 4-prong drapery pleat hooks to bite deeply into the buckram without bending under the weight of blackout-lined fabric. For creating crisp, permanent creases in your finished panels without scorching your fabric, invest in a commercial-grade fabric steamer to train the pleats into place.
How to Calculate Custom Pinch Pleats
Calculating custom pinch pleats is the most math-intensive part of drapery making. You start with your flat fabric width and subtract your side hems and hardware returns/overlaps. The remaining fabric must be perfectly divided into two components: the pleats (the fabric folded and sewn together) and the spaces (the flat gaps between the pleats). If your math is off by even an eighth of an inch, your last space will be too narrow, ruining the symmetry of the panel. PleatPerfect handles this complex distribution instantly, ensuring your pleat take-up and spacing are perfectly balanced. We even generate a virtual tape measure, showing you exactly where to place your pins on the flat fabric panel so you can sew with confidence.
Enter the flat width your panel has after the side hems are turned, not the width you cut. Two 1.5" double side hems eat 6" of a panel, and feeding the cut width in instead inflates every pleat on the tape.
The spacing geometry is the same for pinch, goblet, box and inverted box pleats: once the flat width and the finished width are fixed, so is the fabric each pleat has to swallow. What the style changes is how that take-up is folded and how much fullness you want in the first place, which is a decision you make before you cut, by choosing the flat width you buy.
Frequently Asked Questions
How do you calculate pleat spacing for curtains?
Subtract the hardware return and the center overlap from the finished panel width, then divide what is left by the number of spaces, which is one less than the number of pleats. A pleat sits on the return corner so its hook rides the end bracket, and another sits at the head of the overlap so its hook rides the master carrier, which leaves the flat spaces strictly between pleats. That flat space is the figure this calculator reports. For pinch pleats, the fabric between pleats (called the 'space') should be 3.5" to 4" wide. The pleat itself consumes 4-6" of fabric depending on the pleat style and desired fullness ratio.
What is the standard fullness ratio for drapery?
Standard fullness is 2.5× the finished width — a 100" wide window needs 250" of flat fabric. For pinch pleats, use 2.5-3× fullness. For goblet pleats, use 2.5×. For rod pocket or tab top, use 1.5-2×. Ripple fold (contract/hospitality) is the exception: its 60, 80, 100 and 120 percent options are snap-tape spacing designations rather than multipliers, and they work out to roughly 1.6×, 1.8×, 2.0× and 2.2× the rod width. Never read the 120 percent option as a multiplier of 1.2 — that is little more than half the fabric the job needs. More fullness creates a richer, more luxurious appearance.
What is the difference between pinch pleats and goblet pleats?
Pinch pleats fold the fabric into 2-3 tight fingers pinched together at the top, creating a crisp, tailored look. Goblet pleats form an open cup or tulip shape stuffed with batting, creating a softer, more formal appearance suited to traditional interiors. Both use the same pleat spacing calculations but consume different amounts of fabric.