There is a single mistake that accounts for most curtains looking wrong, and it is not the fabric or the colour. It is hanging the rod at the top of the window frame — which is where the drill instinctively goes, and which makes the window look smaller than it is.
Everything below follows from fixing that.
Height
The eye reads the top of the curtain as the top of the window. Mount higher and the whole window appears taller, and the ceiling with it.
- Safe default: 15 to 20 cm above the frame.
- Better: halfway between the top of the frame and the ceiling.
- Best for ceilings under about 2.7 m: at the ceiling, or on a ceiling-mounted track.
- Very high ceilings (over 3 m): back off — around 10 cm below the ceiling, or the drop becomes absurd.
Width
The rod should extend 15 to 20 cm beyond the frame on each side. That gives the open panels somewhere to stack that is not the window.
This is not only aesthetic. Curtains that stack over the glass block daylight every day of the year, in a room you chose partly for its window.
Length
Floor length, essentially always. Panels that stop 10 cm above the floor look like a mistake, and they let light under the hem.
Two acceptable finishes: kissing the floor, which is crisp and tailored, or a 2 to 5 cm break, where the fabric just touches and softens. The break is more forgiving of uneven floors and of the fact that fabric drops slightly over time.
Heavy puddling — 15 cm or more pooled on the floor — photographs beautifully and collects dust in a real house.
Special cases
A radiator under the window is the one situation where floor length is wrong. A panel draped over a radiator sends its heat up behind the fabric and against the glass, which is the most efficient way to heat the street. Use sill-length panels ending just above the radiator.
Bay windows need a bendable track rather than straight rods, mounted above the whole bay, with a panel at each return so the corners close.
Renting limits drilling but not much else. Reuse the existing brackets and simply buy longer panels; a rod moved up 20 cm on existing fixings is rarely possible, but a longer drop on the same rod still improves the proportions.
The short version
- 15-20 cm above the frame minimum; halfway to the ceiling is better.
- Extend the rod 15-20 cm past the frame on each side.
- Panel width totalling 2-2.5× the rod length.
- Floor length: kissing, or a 2-5 cm break.
- Sill length only over a radiator, or in a kitchen or bathroom.
- Match the height across every window in the same room.
Getting the measurements right before ordering is covered in the curtain measuring guide, and mounting high and wide is also the main fix for blackout curtains that still let light in.
