How wide should curtains be compared to the window?

The combined flat width of your panels should be about 2 to 2.5 times the width of the window or rod. For a 48-inch window, that is roughly 96 to 120 inches of panel total, usually split between two or three panels.

How high should I hang curtains?

On a standard 8-foot wall, mount the rod 4 to 6 inches above the window frame. For a taller, grander look, hang it 1 to 2 inches below the ceiling or crown molding. Higher rods make the whole wall feel taller.

What length curtains should I buy?

Measure from where the rod sits down to the floor, then round up to the nearest stock size — 63, 84, 95/96, 108, or 120 inches. For a floor-skimming "float," choose the length that lands about half an inch above the floor.

Should curtains touch the floor?

For most modern rooms, yes — either floating half an inch above the floor or just kissing it. Short curtains that stop above the sill (outside kitchens and baths) tend to make the room look unfinished and the ceiling lower.

How many curtain panels do I need?

Plan one ready-made panel for every 24 to 30 inches of rod width to keep proper fullness. A 60-inch rod usually needs two to three panels; a 100-inch rod needs about four.

How wide should the rod be?

Extend the rod 8 to 12 inches past each side of the window frame so open panels clear the glass. That adds up to a rod roughly 16 to 24 inches wider than the window itself.

Curtain and Drapery Size Guide: Length, Width, and Hanging Height

A curtain size guide with the real formulas: how wide your panels should be, what length to buy, and how high to hang the rod — with tables and examples.

Two numbers decide whether curtains look tailored or like an afterthought. Width: your panels, combined, should measure about two to two-and-a-half times the width of the window or rod, so they hang in soft folds instead of stretching flat. Length: most modern rooms look best when panels just kiss the floor, which means buying for the distance from the rod down — usually 84, 96, or 108 inches off the shelf. Hang the rod high and wide, and almost any window looks taller and grander than it is.

Here are the formulas, the standard sizes, and the clearances for every common window.

Start with where the rod goes (it changes everything)

Before you measure for panels, decide where the rod will live. Hanging height and rod width affect every other number, and they are the cheapest way to make a window look more expensive.

Height: hang high. Place the rod 4 to 6 inches above the window frame on a standard 8-foot wall, or — for the most dramatic effect — closer to the ceiling, 1 to 2 inches below the crown or ceiling line. The eye reads the fabric as the window, so a high rod stretches the whole wall upward.
Width: hang wide. Extend the rod 8 to 12 inches past each side of the window frame (more on wide windows). This "stack-back" lets open panels clear the glass, so you get full daylight and the window looks broader.

Decision	Standard	Dramatic / tall look
Rod height above frame	4–6 in.	1–2 in. below ceiling line
Rod extension past each side	8–12 in.	Up to 18 in. on wide windows
Total rod width	Window width + 16–24 in.	Window width + up to 36 in.

Curtain length: the four ways panels meet the floor

Curtain length is measured from the top of where the panel hangs (the rings or rod pocket) down to your target hem. That means it depends on rod height, not just window size — measure after you have placed the rod.

Hem style	Where it lands	Best for
Float (recommended)	½ in. above the floor	Everyday rooms, easy to open and clean
Kiss / brush	Just touching the floor	A polished, tailored look
Break	Pools 1–2 in. on the floor	Soft, relaxed, traditional rooms
Puddle	3–8 in. of fabric on the floor	Formal, dramatic; not for high-traffic spots
Sill / apron (short)	At the sill or 4 in. below it	Kitchens, bathrooms, over radiators or counters

How to choose a stock length. Measure from the rod to the floor, then round to the nearest size you can buy. Standard ready-made lengths in the US are 63, 84, 95/96, and 108 inches, with 120-inch panels available for tall walls.

Rod hung ~84 in. off the floor → buy 84 in. panels for a float, 95/96 in. if you hung near the ceiling.
Rod hung ~96 in. off the floor → buy 96 in. panels to float, 108 in. to break.
Rod hung ~108 in. (tall ceilings) → buy 108 or 120 in. panels.

When a measurement falls between sizes, size up and have the hem taken in. Short curtains are the most common drapery mistake — they make the ceiling feel lower and the whole window look unfinished.

Curtain width: the fullness formula

A single flat panel pulled across a window looks like a bedsheet on a rod. Fullness is what makes drapery read as drapery.

Total panel width = window (or rod) width × 2 to 2.5

That total is the combined width of all panels, flat, before they gather. Then divide by how many panels you want.

Worked examples for a 48-inch-wide window:

Look	Fullness	Total flat width needed	Typical panels
Tailored, light fullness	× 2	~96 in.	Two 50 in. panels
Standard, soft folds	× 2.25	~108 in.	Two 54 in. panels
Luxe, very full	× 2.5	~120 in.	Two 54 in. panels, or three

A quick rule for ready-made panels, which usually run 50 to 54 inches wide each: use one panel for every 24 to 30 inches of rod width to keep proper fullness. A 60-inch rod wants roughly two to three panels; a 100-inch rod wants four.

Sizing by window type

Window	Rod width	Length approach	Panels (50–54 in. each)
Standard double-hung (~36 in.)	~52–60 in.	Float at 84–96 in.	2
Wide picture window (~72 in.)	~88–96 in.	Float at 96 in.	3–4
Sliding glass door (~80 in.)	~96–104 in.	Float at 96–108 in., stack panels off the glass	4
Bay window	Measure each section; use a bay rod or three rods	Match length across all sections	1–2 per section
Narrow / tall window	Extend rod wider than usual to add visual width	Hang near ceiling, float	2

For a sliding door or a wide span, the panels need somewhere to go when open — that is the stack-back. Plan an extra 8 to 12 inches of rod on each side so daylight isn't half-blocked all day.

A worked example, start to finish

Say you have a 48-inch-wide living room window on an 8-foot wall, and you want a soft, modern, floor-skimming look.

Rod height: mount it 6 inches above the frame — roughly 90 inches off the floor.
Rod width: extend 10 inches past each side → about a 68-inch rod.
Length: measure rod-to-floor (~89 in.), buy 95/96-inch panels for a clean float.
Width: rod is 68 in., so target ~150 inches of flat panel for full folds → three 54-inch panels, or two if you accept lighter fullness.

That is the whole calculation. Fabric choice — linen, cotton, blackout, sheer — is the next decision, and it changes how the folds fall and how much light you keep; our guide on how to choose curtains for modern rooms walks through weight, color, and lining.

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The short version

Hang the rod high (4–6 inches above the frame, or near the ceiling) and wide (8–12 inches past each side). For length, measure rod-to-floor and round up to 84, 96, or 108 inches, aiming for a float just off the floor. For width, multiply the rod width by 2 to 2.5 to get the total flat panel width, then split it into panels — about one per 24 to 30 inches of rod. High, wide, full, and floor-length: four moves that make any window look tailored.

Frame your windows with intention — Shop Decor.