How to Get the Right Curtain Width for Any Window

Choosing curtains that fit just right can feel tricky, but it doesn't have to be. All you need is a tape measure, a bit of math, and an eye for style. Below you'll find a step‑by‑step method that works for any window, whether it's a narrow kitchen pane or a soaring living‑room bay.

Step 1: Measure Your Window Opening

Start by measuring the width of the actual window frame, not the glass. Place the tape at the inside edge of each jamb and write down the number. If you want your curtains to frame the window rather than hug it, add a few extra inches on each side—most designers recommend 4‑6 inches total.

Example: A window that measures 48 inches wide becomes 54‑56 inches of curtain width when you add that extra framing space.

Step 2: Decide on Curtain Style and Fullness

Different looks need different fabric amounts. For a crisp, tailored look, go with a 1.5 × fullness ratio (meaning the fabric width is 1.5 times the window width). For a soft, gathered look, aim for 2 × or even 2.5 × fullness. Multiply your window width (plus any extra framing) by the ratio you chose to get the total fabric width you’ll need.

Quick tip: If you buy ready‑made panels, each panel usually covers about 42‑48 inches when opened. Divide your total fabric width by the panel width to see how many panels you need. Two panels of 48 inches each cover a 96‑inch span, which works well for a 48‑inch window with 2 × fullness.

Don’t forget the rod. A sturdy pole that extends 3‑6 inches beyond each side of the window adds visual balance and gives the curtains room to stack when open.

Now you have the numbers you need to shop confidently: window opening, extra framing, fullness ratio, and rod length. Grab curtains that match those specs, and you’ll avoid the dreaded curtain‑too‑short or curtain‑too‑tight problem.

Still unsure? Take a photo of your window, jot down the measurements, and compare them with the product details on the retailer’s page. Most sites list the finished width of each panel, so a quick calculation will confirm a perfect fit.

With these simple steps, you’ll get curtains that look polished, hang nicely, and let you enjoy your space without the hassle of trial‑and‑error.