How to measure
- 01
Measure the actual working rod or track width; if hardware is not installed, record the window-frame width and your planned side extensions separately.
- 02
Measure the drop from the reference point stated for the selected heading—not from an unrelated edge of the window.
- 03
Check whether a package contains one panel or a pair, then compare total flat fabric width rather than the label width alone.
- 04
Recheck the selected product, tape, hooks, carriers, and fabric before ordering or cutting.
Apron is an endpoint, not a standard size
The sill height and rod position vary, so apron curtains cannot be selected from window height alone.
Keep the wall composition in view
A few inches can look balanced on one window and awkward on another. Mark the proposed line temporarily before ordering.
Check product construction
Tabs, grommets, rings, and tracks change the starting reference and therefore the final drop.
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.
- 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.