How to size curtain rods
Measure the surface, then the overhang
Curtain rod length = window width + 6–12″ on each side (so curtains stack off the glass when open) + 1–2″ for the finials. Most rods are sold in adjustable telescoping ranges (e.g., 28–48″, 48–84″).
Standard sizes vs. your actual surface
Manufactured "standard" sizes assume textbook measurements. Older homes, custom furniture, and non-standard windows often deviate by 1–3″. If the measurement falls between two stock sizes, choose the larger; it's easier to hem or tuck excess fabric than to add length you don't have.
Mounting and clearance
Mount brackets at the rod's 1/4 and 3/4 points; rods longer than 60″ need a centre bracket to prevent sag. Heavy curtains and metal rods need brackets anchored into wall studs or with toggle anchors rated for 25–40 lb.
Common mistakes
- Measuring once. Surfaces are rarely perfectly square; take the smallest of three measurements.
- Forgetting shrinkage. Cotton items can lose 3–5% on the first wash.
- Ignoring drape. Heavier fabrics need an extra inch or two to hang correctly.