How to Measure For Curtains the Right Way

Curtains that fit transform a room. Curtains that miss by two inches are all anyone notices.

This guide covers every measurement that matters, in order. By the end, you’ll know:

• Whether to mount inside or outside the frame, and why that choice comes first
• How wide and long your curtains should be, with exact multipliers
• What to adjust for bay, wide and above-sink windows
• How measuring gets simpler with no-drill, trim-mounted brackets

Start Here: Inside Mount vs. Outside Mount

Before you measure anything, decide where your hardware will live. Everything after depends on it.

Inside mount hangs the rod inside the window recess: a clean, built-in look for café curtains and small windows. It needs a precise inside-frame width and lets some light around the edges.

Outside mount hangs the rod above and beyond the frame, on the wall or the trim. It makes windows look larger, blocks light better and forgives small measuring errors. Most curtains hang this way.

No-drill, trim-mounted brackets are an outside mount with a shortcut. Kwik-Hang brackets tap into the top corners of your window casing, so the trim sets the spot and there’s nothing to mark.

What You’ll Need to Measure Curtains

• Metal tape measure (cloth tapes stretch and lie)
• Notepad or phone for your numbers
• Pencil or painter’s tape for marking
• Level and step stool if you’re mounting hardware on the wall

Using trim-mounted brackets? Skip the level and the marking.

How to Measure Curtain Width

Measure your window’s width from outside edge to outside edge of the frame.

Rod width: extend the rod 3–6 in. past the frame on each side. Hanging heavy drapes? Go wider, up to about 20% of the window’s width in total. That room lets open panels stack beside the glass instead of over it (the buffer is called stack-back). Rod shopping? See how to choose the right curtain rod.

Panel width: total fabric is a multiple of window width, based on fullness:

• Standard fullness: 2x the window width
• Deluxe fullness: 2.5x the window width
• Maximum fullness: 3x the window width

Never buy curtains that match your window’s exact width. A 45-in. panel on a 45-in. window looks tight and unfinished. Panels typically come 48 in. wide, so divide your total fabric number by 48 and round up for your panel count.

How High Should You Hang the Curtain Rod?

Mount a wall rod 4 to 8 in. above the window frame, or up to 12 in. with tall ceilings. A higher rod makes the window look taller.

Wall mounting means marking both spots and checking them with a level.

Trim-mounted brackets work differently. The rod sits right at the top of your window trim, so there’s no height to choose and nothing to level. You trade the height trick for a straight rod with zero marking. For renters who can't drill anyway, it's an easy trade.

How to Measure Curtain Length

Curtain length (also called drop) depends on your window and the style you want.

For shorter windows:

• Sill length: curtains hover just above the windowsill. Measure from the top of the window frame to ½ in. above the sill.
• Apron length: curtains extend slightly below the casing. Measure from the top of the frame to 1 in. below the sill.

For floor-length styles:

• Hover (sometimes called float): curtains stop about 1 in. above the floor.
• Kiss: curtains barely graze the floor. Measure from the top of the rod to the floor, including curtain rings if you use them.

For a dramatic look:

• Break: curtains touch the floor with a slight bend. Measure frame to floor, then add 1 in.
• Puddle: curtains pool on the floor. Measure to the floor, then add 1–3 in. (minimal), 3–6 in. (moderate) or 6–8 in. (opulent).

For style-by-style depth, see our curtain length rules.

Standard Curtain Sizes and Which to Choose

Standard curtain lengths are 63, 84, 96, 108 and 120 in. Map your measurement to the closest one:

If your number lands between sizes, buy the longer one and have it tailored. Hemming down is easy; adding fabric isn’t.

Measuring for Different Window Types

Bay windows: treat each section of the bay as its own window. Measure each frame separately, then use one rod per section or a bay rod that bends at the angles.

Wide and double windows: the fullness math doesn’t change; the support does. Add a center support bracket for windows wider than 60 in. and a second bracket for windows 121 in. and up. Going past 120 in.? Our extra-long curtain rod guide covers sizing and support.

Above-sink and kitchen windows: café curtains over the bottom half are the classic pick. Measure the inside-frame width and hang at the halfway point. Standard café lengths are 24 and 36 in.

Measuring When You’re Using No-Drill Brackets

Trim-mounted brackets simplify two of the measurements above.

Both measurements you already took carry over. There's no rod height to choose (it sits at the top of the trim), and your fullness math doesn't change. Measure length from the top of the trim to your endpoint: sill, floor or puddle.

One check before you order: Kwik-Hang brackets need traditional wooden trim between ½ in. and 1 in. wide. They're not recommended for oak or other hardwoods, PVC, MDF, metal or crown molding. Each holds up to 20 lbs. Singles project 3 in.; doubles project 4 in. and layer sheers behind drapes.

The install needs no tape measure: set each bracket at a top corner, tap with a hammer and hang. See the full walkthrough in our how to hang curtains guide.

Double-Check Before You Buy

One last pass before you order:

• Width includes fullness (2–3x the window), not just the window’s width
• Length starts from the right point: the rod for kiss styles, the frame or trim for the rest
• Mount type and rod are decided (both change the numbers)
• Everything is written down, rings included if you’re using them

Two extra minutes here beats a return label.

Curtains Minus the Complexity

Measuring is the hard part, and you’ve just done it. The hang is the easy part.

Kwik-Hang’s no-drill, damage-free curtain rod brackets keep it that way for renters and DIYers. No measuring the hardware, no holes, no wall repair when you move out. The only measuring that matters is the curtains themselves.

Place. Tap. Hang. Shop no-drill curtain rod brackets today.

Frequently Asked Questions

How wide should curtains be for a window?

Total fabric should run 2 to 3 times the window’s width: 2x for standard fullness, 3x for maximum. The rod itself should extend 3–6 in. past the frame on each side.

How high should you hang curtains above the window?

Mount wall rods 4 to 8 in. above the frame, or up to 12 in. with tall ceilings. Trim-mounted no-drill brackets sit at the top of the trim, so there’s no height decision.

How many curtain panels do I need per window?

Divide your total fabric width by the panel width, usually 48 in., and round up. A 60-in. window at standard fullness needs 120 in. of fabric, which means three 48-in. panels.

Should curtains touch the floor or hang above it?

Both work; it’s a style call. Hovering about 1 in. above the floor is the clean, low-maintenance default. Kiss and break styles read more tailored, while puddles suit formal rooms but collect dust faster.

How do you measure for curtains without drilling?

With tap-in trim brackets, measure just two things: window width for fullness and top-of-trim to your endpoint for length. The hardware itself needs no measuring. See every no-drill option in our guide to hanging curtains without drilling.