Roman Shade Fold Spacing Calculator

Calculator Inputs

Formula Used

• Usable height = Finished height − Top allowance − Bottom allowance
• If you choose fold count: Fold spacing = Usable height ÷ Fold count
• If you choose target fold size: Fold count ≈ Usable height ÷ Target size (then rounded)
• Fold line #i from bottom = Bottom allowance + i × Fold spacing
• Optional rings: ring span = Usable height − first offset − last offset, then step = ring span ÷ (fold count − 1)
• Optional cords: clear width = Width − 2×side margin, then cord spacing = clear width ÷ (cords − 1)

How to Use This Calculator

1. Select a unit system and enter your finished shade height.
2. Add top and bottom allowances for hems, pockets, or headers.
3. Choose either a fold count or a target fold size.
4. Optional: add ring row offsets to plan lift placement.
5. Optional: add width, cords, and side margins for cord spacing.
6. Press Calculate to see fold marks above the form.
7. Export the table as CSV or PDF for your work area.

Why fold spacing matters

Roman shades look clean when folds stack evenly and cords share load. If spacing drifts, the fabric balloons, the bottom rail tilts, and the shade can bind near the headrail. Repeatable fold marks also speed sewing because each pocket uses the same geometry. This calculator turns a finished height into fold lines you can mark before stitching.

Allowances and usable height

Start with finished height, then subtract top and bottom allowances. The top allowance covers a header seam, mounting wrap, or hook tape. The bottom allowance covers a hem, weight pocket, or trim. Removing these zones yields the usable height where folds form. Separating allowances lets you compare inside versus outside mounts and different hem styles without rebuilding the layout.

Count method and target method

Two planning styles are common. With fold count, spacing equals usable height divided by the count, giving identical fold sections. With target size, the tool estimates a count by dividing usable height by the target, applies your rounding rule, and then recomputes the exact spacing that fits the shade. This keeps folds consistent across a room while respecting real window measurements.

Lift ring rows and cord spacing

Lift rings should align vertically so cords rise smoothly. Optional ring offsets place the first row above the bottom hem and the last row below the top usable area, reducing bulk at seams. The remaining span is split into equal steps to create ring rows matched to fold sections. For width, cord spacing is estimated from finished width minus side margins, divided by cord gaps.

Applying the results in production

The results table lists fold line distances from the bottom edge, plus ring row distances when offsets are set. Transfer marks to fabric on a straight grain, confirm both edges, then stitch tapes and pockets. Export CSV for cut lists and QA checks, or export PDF for a printed work order. Recalculate whenever hems, liners, or mounting style change before final pressing and packaging.

FAQs

1) What fold spacing works best visually?
Answer: Many makers prefer 15–25 cm or 6–10 in folds, depending on fabric weight and window height. Use fewer, larger folds for thick fabrics and taller windows, and more folds for lighter fabrics and shorter drops.

2) Do I measure from the top or bottom?
Answer: This tool reports distances from the bottom edge upward. Mark the bottom hem first, then measure up to each fold line. This keeps pocket spacing consistent even if the top header treatment changes.

3) How do I choose the fold count?
Answer: Pick a count that matches nearby shades or reaches your preferred fold size. For most residential heights, 5–8 folds is common. If the spacing looks too tall or short, adjust the count and recalculate.

4) What ring offsets should I use?
Answer: A practical starting point is 2–3 cm or about 1 in above the bottom hem and the same below the top usable area. Increase offsets if seams are bulky or if you add a thick liner.

5) Does cord spacing depend on fold spacing?
Answer: Cord spacing is mainly driven by width and the number of lift cords. Fold spacing affects vertical stability, while cord spacing affects horizontal balance. Wide shades typically need additional cords to prevent sagging or skew.

6) Can I use this for lined shades?
Answer: Yes. Enter allowances that reflect your liner hem and header build-up. Lining can change how crisp folds appear, so you may prefer slightly larger fold spacing. Recalculate after test-folding a small sample.

Example Data Table