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Curtain Size Calculator Guide
Panel count and length — with fullness treated as the thing that actually decides whether curtains look expensive.
Fabric width = rod width × fullness ratio
Panels = fabric width ÷ panel width, rounded up
A 60in rod at 2× fullness needs 120in of fabric — that's 3 panels at 50in each, not 2.
Fullness Is Everything
This is the single thing that separates curtains that look tailored from curtains that look like a bedsheet on a pole.
Two panels exactly as wide as the window will hang flat and stretched with no folds at all. You want roughly twice the rod width in fabric so the curtain gathers into proper vertical folds — 2× is the sensible target, 2.5× for pleated headings, and 1.5× is the floor below which it stops reading as a curtain.
Hang High and Wide
Mount the rod close to the ceiling rather than just above the window frame, and let it extend 8–12in past the glass on each side.
High makes the window look taller because the eye reads the full drop as window. Wide lets the panels stack off the glass when open, so you get all your daylight and the window looks bigger than it is. Both cost nothing extra and both are more or less free upgrades that most people skip.
Length Reads as Intent
Curtains ending halfway down the wall look like a mistake. The three intentional options are: floating about half an inch off the floor, breaking with a couple of inches of pool, or a full puddle.
Float is the practical choice — it looks crisp and you can vacuum under it. Puddle is a deliberate luxury statement that collects dust and needs rearranging every time someone walks past. Sill length is legitimate too, but generally for a radiator or a kitchen, not a living room.
Measure the Drop From the Rod, Not the Window
The length you need is from where the curtain hangs to where you want it to end — and where it hangs depends on the heading.
Rings and clips hang the fabric below the rod, so you lose a couple of inches. A rod pocket swallows the rod inside the fabric. Grommets sit somewhere between. Get this wrong and you've bought beautiful curtains that end three inches short, which no amount of steaming will fix.
Two Panels Is a Habit, Not a Rule
Curtains come in pairs so people buy pairs. But the fabric you need is a function of your rod, and a wide window at proper fullness often needs three or four panels.
An odd number is fine if the curtains stay closed on one side, or if you're using a single panel drawn to one side deliberately. Buy for the fullness, not for the symmetry of the packaging.
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