How to measure
- 01
Measure the usable rod or track span and record decorative finials, returns, bends, or overlaps separately.
- 02
Measure the finished drop from the attachment point named for the selected heading to the intended lower endpoint.
- 03
Convert inches and centimeters only after recording the original measurement; use 1 inch = 2.54 centimeters.
- 04
Compare the calculated target with the exact product label, package quantity, heading take-up, and manufacturer tolerance before ordering.
WORKED CALCULATION
Extra-wide opening example
- Working track
- 144 in (365.8 cm)
- Fullness
- 2×
- Panel count
- 4
72 in (182.9 cm) flat width per panel; 288 in total
Overlaps, returns, heading take-up, seams, and manufacturer tolerance can change the product plan.
Recalculate with your measurementsStart with one complete span
For one treatment across a large opening, calculate from the full working rod or track. Do not size each glass pane separately unless separate curtain sections are intentional.
Divide only after calculating total width
Panel count organizes seams, draw direction, and handling. It does not reduce the total flat-fabric target required by the chosen heading fullness.
Check package language
An “extra-wide” label may describe one flat panel, one finished pleated panel, or a package pair. Add the usable width of every included panel before comparison.
Expect more stack and fabric
Wider and fuller treatments occupy more space when open. Fabric body and heading construction affect that stack; use a system chart or sample where clearance is critical.
Before you order or cut
Measure the actual window and selected product. Finished sizes, fullness, header take-up, hardware geometry, and manufacturer tolerances vary. Fabric can shrink, stretch, or behave differently by composition. Measurements do not guarantee fit, privacy, water containment, installation, load capacity, or structural safety. Use the selected product instructions, and have a professional workroom verify expensive custom-fabric orders.
SOURCE NOTES
What this page is based on
Measurements here combine mathematical results with labeled commercial conventions and design recommendations. Disagreements are kept as ranges rather than averaged into a false standard.
- BETYDLIG/RÄCKA/HUGAD buying guide — Measure your windowIKEA · reviewed 2026-09-11
Primary manufacturer guide: add at least 6 in each side, add 6 in above, and use 2–2.5× rod width for panel planning.
- MATILDA curtain product specificationsIKEA · reviewed 2026-09-11
Manufacturer product guidance presents 1.5×, 2×, and 2.5× rod/track-width options for light through extra-full looks.
- Buying curtainsJohn Lewis & Partners · reviewed 2026-09-11
Retailer/workroom guidance on pole extension, hanging references, sill/floor endpoints, ready-made metric ranges, and double fullness.