Measurement guide
How to measure a roman blind
This is a planning sequence for entering figures into the calculator. It is not a fitting standard, a child-safety certificate, or a substitute for a site visit.
1. Decide recess or exact
- Recess fit starts from the plaster or timber opening. The calculator then deducts the width and drop clearances so the blind can operate.
- Exact fit is the finished size you want, including any overlap outside the opening.
2. Width
- Measure the opening or the intended coverage at the top, middle and bottom.
- For a recess, the smallest width is the cautious planning figure.
- For an outside or exact fit, use the coverage you actually want, not the glass alone.
3. Drop
- Measure left, centre and right from the intended top line to the sill or overlap.
- Note window handles, tiles, vents and seat cushions that the hem must clear.
- The calculator does not deduct headrail thickness automatically. If the system sits inside the recess, include that in the drop you type or in the drop clearance.
4. Raised stack
When a roman blind is up, the folds sit in a stack at the top. The planner shows a rough stack height from fold count. That figure is only a visual estimate. Deep cascade folds and thick interlining take more room than a flat cotton lining.
5. Cords and child safety
Loop cords and inner cords can be a hazard. Check the current UK product safety rules for blinds, including any requirement for breakaway devices, tensioners or wand operation, before specifying hardware. This page does not certify a design against those rules.