How to Calculate Curtain Width for the Right Fullness
How much curtain fabric do you need?
Curtains need enough fabric to create folds when they're closed. If you simply buy curtains equal to the width of your window, they may look flat and stretched rather than full.
The amount of fabric you need depends on the curtain rod width, heading style and fabric.
The Basic Fullness Formula
As a starting point:
Total curtain fabric width = rod width × fullness
For example, if your rod is 180 cm (71 in) wide:
- 1.5× fullness: 270 cm (106 in) total fabric
- 2× fullness: 360 cm (142 in) total fabric
- 2.5× fullness: 450 cm (177 in) total fabric
You then divide the required total width between your panels.
Which Fullness Should You Choose?
There is no single multiplier that works for every curtain.
As a general starting point:
- 1.5×: simpler, less gathered look
- 2×: fuller, more traditional look
- 2.5× or more: particularly full or decorative treatments
The appropriate amount also depends on the curtain heading and fabric. Always check the manufacturer's recommendations when buying ready-made curtains.
Measure the Rod, Not Just the Window
Your fullness calculation should be based on the area the curtains need to cover, which is usually related to the rod width rather than simply the glass or window frame width.
If your curtains are intended to remain permanently open as decorative side panels, you may need less fullness than curtains that will regularly be closed.
Don't Forget Panel Width
Once you've calculated your total required fabric width, divide it by the number of panels you're using.
For example:
360 cm total ÷ 2 panels = 180 cm per panel
Check the actual finished width of the curtains you are buying, as manufacturers can list panel dimensions differently.
Check Your Curtain Width
Use the Nooked Curtain Calculator to calculate your required curtain dimensions from your measurements.
Calculate Your Curtain Size →
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