How to Measure Curtains on a Rail or on a Pole?
This measurement is suitable for the following curtain heading types:
Pencil Pleat, Eyelet, Tab top, Triple Pleat and Goblet Top.
The curtain rail or pole should be positioned 15cm (6") above the window recess and extend 15 to 20cm (6" to 8") on both sides.
To measure the width, take the total width of the rail without the finials. Then add about 5cm (2") to allow the hanging curtains to overlap in the middle when they are closed.
To measuring the drop, you need to decide whether you want your curtains to fit below the sill or to the floor. If you want your curtains to fall below the sill, then measure from the top of the rail to about 15cm (6") below the sill
(See fig. 1 & 3 )
If you want your curtains to be floor length, then measure from the top of the rail to about 1.5cm (1") from the floor (See fig. 1 & 3)
For pencil pleat, triple pleat or goblet top curtains, measure the drop from the eye - the small metal ring at the bottom of each curtain ring. This will prevent the pole or rings from being obscured by the curtain (See fig. 2 & 4).