Source policy
Sources & assumptions
Guidance is sourced; the calculator itself is driven by your measurements and visible arithmetic.
Measurement guidance
The Shade Store — How to Measure for Curtains
Used to cross-check the distinction between window width, rod span, fullness, outside-mount extension and floor-length measurement.
No hidden perfect-size database
Ready-made widths, header construction, rods and installation rules vary. Nenxo asks for the product width and bracket inset you are actually considering.
Independent tool
Nenxo is not affiliated with curtain, rod or home-furnishing manufacturers.