Curtain Rods: Why Rods Run Wider Than Windows
A rod that only spans the glass traps curtains over the window. Overhang on both sides lets them stack clear and the room gain light.
What is the Curtain Rod Length Calculator?
Enter the window width and how far the rod should extend past each side, and the tool adds both overhangs to the width. The overhang lets curtains stack clear of the glass when open, which is the point of the extra length.
How to use it
- Measure the window width in centimetres.
- Enter the overhang you want on each side.
- Click Calculate Rod Length.
Worked example
120 cm wide with 15 cm overhang each side needs a 150 cm rod.
How much overhang is typical?
Around 10 to 20 cm per side suits most windows, with wider overhangs for heavy or blackout curtains.
Frequently asked questions
Should the rod clear the frame?
Yes, mount it above the frame so curtains hang clear of the window and its handles.
What if the wall space is tight?
Use the largest overhang that fits, keeping both sides even where possible.