First compute usable width:
usable = track_width − returns_left − returns_right − overlap
Balanced end method:
center_spacing = usable / pleats
edge_gap = center_spacing / 2
Fixed end method:
center_spacing = (usable − 2 × fixed_edge_gap) / (pleats − 1)
Fabric estimate:
flat_fabric ≈ finished_width + (pleats × pleat_stack_depth)
Use a larger stack depth for deeper pleats.
- Measure track width where the curtain will hang.
- Add left and right returns if needed.
- Enter overlap for a center meeting pair.
- Pick the number of pleat groups across width.
- Choose balanced or fixed edge spacing method.
- Press calculate and mark the pleat center positions.
| Track | Returns L | Returns R | Overlap | Pleats | Stack | Panels |
|---|---|---|---|---|---|---|
| 240 | 10 | 10 | 5 | 8 | 6 | 2 |
| 300 | 12 | 12 | 7 | 10 | 7 | 2 |
| 180 | 8 | 8 | 4 | 6 | 5 | 1 |
For outdoor garden panels, keep end gaps slightly wider to reduce snagging.
Spacing targets for stable hanging
Consistent pleat spacing helps panels slide smoothly and keeps the hemline straight. For most medium-weight curtain fabrics, a center-to-center spacing that produces 6–12 pleat groups per 2 meters of track is common. The calculator outputs an exact step size so your marks remain uniform from the first hook to the last.
Returns and overlap to reduce light gaps
Returns pull fabric back toward the wall, which reduces side gaps and improves the “wrapped” look. Overlap lets two panels cover the center join. The usable width formula subtracts both returns and overlap, so your pleat centers align to the true working span, not the raw rail length.
Balanced edges versus fixed edge gaps
Balanced edges set the end gap to half a spacing step, producing a symmetrical pattern. Fixed edges are helpful when you must keep end pleats away from brackets, tiebacks, or garden hooks. If fixed edges are too large, the calculator warns you because the remaining span cannot fit the requested pleat count.
Fabric take-up and fullness estimates
Pinch pleats consume extra fabric as folds stack together. The calculator estimates take-up using pleats × stack depth. If your pleats are deeper, increase stack depth to avoid under-ordering. The resulting fullness ratio (flat ÷ finished) helps you compare setups; higher ratios look richer but add weight and cost.
Marking workflow for accurate results
After calculating, start from the usable left edge and mark each pleat center using the position list. Keep marks light until you confirm the last position lands correctly. When splitting into panels, distribute any extra pleat groups near the overlap side for a cleaner center meet and consistent visual density.
1) What does “usable width” mean?
Usable width is the rail length available for pleat placement after subtracting left return, right return, and any center overlap. It is the baseline used to compute center-to-center spacing.
2) Should I use balanced or fixed edge gaps?
Balanced edges create a symmetrical pattern and work for most installations. Choose fixed edge gaps when you must avoid brackets, tieback points, or outdoor hooks near the ends.
3) How many pleat groups should I choose?
More pleat groups produce a finer, more tailored look; fewer groups look bolder and can suit heavier fabrics. Start with 8–12 groups for typical two-panel setups and adjust for style.
4) Why does stack depth change fabric estimates?
Stack depth represents extra fabric consumed by folding each pleat group. Deeper pleats or thicker fabric increase take-up. Raising stack depth reduces the risk of ordering too little width.
5) Can I use inches and centimeters?
Yes. Select a unit system and keep all inputs in the same units. The calculator keeps results in that unit, making the position marks consistent on your measuring tape.
6) How do I split pleats across multiple panels?
Divide the total pleat groups across panels as evenly as possible. If the count does not divide cleanly, place the extra group(s) on the panel that forms the center overlap for a neater join.