Correct proportions for drapery window coverings

How do you get successful drapery window coverings?

You decide where all the bits and pieces are going to go.

Briefly, how far the pole or track will go either side of your window, and if you have swags, a cornice or valance, how deep they will be. Plus a few other decisions.


How far up should the cornice board go?

Do you have 'dead' space above your window? Then you could have a valance, cornice or swags fitted to achieve a more elegant finish. Here's a general guide.

Cornice box height above window

The narrowest section of the cornice box should just cover the window as shown here. When the curtains are pulled back they and the cornice are positioned just over the window. This lets in the maximum amount of light while still 'dressing' the window.

Make the depth of the top treatment approximately one fifth of the finished length of the drapes.

The bottom of the treatment should just cover the top of the window frame by a couple of inches.


So the treatment frames the window but doesn't cut out any daylight.

So calculate how deep the top treatment should be, then fix your cornice board accordingly.

You'll also use a board for your drapery window coverings if you want to use a valance. Yes, I know you can buy 'valance kits' which include a curtain track and a track to support the valance. And they're fine for light and casual treatments. But there are reasons why professionals use a board for their drapery.

You want your window treatment to look good, right?

How far up should a pole go?

pole heigth above window

The pole should be placed so the top of the curtains are above the top of the window by a couple of inches. When the curtains are pulled together they completely cover the frame.

Poles and tracks are ideal if you don't have much space above your window. I normally fit them at least 3" (8cms) up, and sometimes more depending on the situation. My rule of thumb is to fit the pole one third of the way up from the top of the window. If the space is large (you could fit a cornice but you prefer a pole) then fit the pole about 4" or 5" up.

How long should the pole or track be?

This depends on the stack back (the wall area the drapes hang against when they are fully open). This stack back size will vary depending on a number of factors.

  • The number of widths in the drapes.
  • The thickness of fabric, lining and interlining (thin fabric and interlining will stack closer together than thick ones).
  • The fullness of the drapes.
  • Whether the tracks are corded or not (corded tracks need a bit more space).

An approximate guide is to add 15% of the window width on either side.

How long should the drapes be?

I prefer floor length drapes every time, but I accept that this isn't always ideal, or even possible. Floor length drapes look more elegant and imposing than sill length ones for drapery window coverings. You can have them just off the floor, just touching, or falling onto it in folds - known as 'puddling'.

position of valance

As with a cornice box, a valance should be positioned so it and the curtains frame the window.

For a really majestic finish you can have your drapery tied back with your own made-up tiebacks, or with sumptuous double tassel ones.

When you have to have sill length drapery, then make it with the same care and attention to detail.

If your drapes are going to hang inside the frame, then have them finish just above the sill. If they will be fitted outside, then make them 4" to 6" longer, depending on the window height.

How to check you have the right proportions

Get some old sheets or any old fabric. Bunch the fabric and pin it up where the drapes are going to hang. Use fabric, paper or card and make a replica valance, cornice or swags. Pin these up as well. This will give you a good idea of how the treatment will look.

It's best to use very plain fabric for this, which is why old sheets are ideal. You're not looking to see the effect of pattern or color, but the proportions. So ask yourself:

  1. Do the various parts of the treatment balance with one another? Is the valance too shallow, or does it look too heavy with the curtains?
  2. Is the overall scheme in proportion with the window and the rest of the room?

By using old sheets, paper and card you can easily adjust your scheme to get it right.


The proportion for your drapery window coverings are tied to window size, shape and position. It's worth spending as much time as necessary on this stage so you get your design just right.

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