Curtain Size Calculator: Panels & Length
Curtains that are too narrow look skimpy; curtains that are too short make the whole window look stubby. Yet most people buy panels by guessing — and “standard” sizes vary wildly between brands.
This free calculator sizes them properly. Enter your curtain rod width and window height, choose your fullness look and length style, and we'll tell you exactly how many panels you need and which standard size to buy — then show you the best-rated curtains in that size on Amazon.
What Size Curtains Do You Need?
Curtains that are too narrow or too short make the whole window look wrong. Tell us your setup and we’ll size the panels properly.
Your curtain size
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Frequently asked questions
How wide should curtains be compared to the window?
For a tailored look, total fabric should be about 1.5x the rod width; for a full gathered look, about 2.25x.
How many curtain panels do I need?
Two panels is standard — one per side. For rods wider than about 80 inches, three or four narrower panels hang better.
What is the standard curtain length?
Common ready-made lengths are 63, 84, 95, and 108 inches. Floor-length panels should just kiss the floor.
How high should I hang a curtain rod?
Mount the rod 4–6 inches above the window frame and 4–6 inches wider on each side — it makes the window look bigger.
Are blackout curtains worth it?
For bedrooms, nurseries, and home offices — absolutely. Look for triple-weave fabric rather than rubber backing.