Window Treatments
Curtain length and hanging height
The rod height decides how tall the room looks; the hem decides whether the room looks finished.
On this page (7 sections)
Short answer
Hang the rod at least 4 to 6 in (10 to 15 cm) above the window casing, and ideally halfway between the top of the casing and the ceiling. Where that gap is under 12 in (30 cm), mount 2 to 4 in (5 to 10 cm) below the ceiling or use a ceiling track. Measure the panel from the rod, not the trim, and subtract the 1 to 2 in (2.5 to 5 cm) of ring or hook drop. Most rooms want a float hem, 1/2 in (1.3 cm) clear of the floor.
The numbers, at a glance
- Minimum above the casing
- 4 to 6 in (10 to 15 cm)Trade practice
- Usual rod height, 8 ft ceiling
- 88 to 93 in (224 to 236 cm)Halfway rule
- Ceiling-mount trigger
- casing to ceiling under 12 in (30 cm)
- Ring or clip drop to allow
- 1 to 2 in (2.5 to 5 cm)
- Float hem
- 1/2 in (1.3 cm) above the floorOur default
- Break hem
- 1 in (2.5 cm) on the floor
- Puddle
- 3 to 6 in (8 to 15 cm)
- Sill length hem
- 1/2 in (1.3 cm) below the sillOr 4 in (10 cm) below the apron
The three rod heights#
There are three defensible positions for a curtain rod and one that is always wrong.
4 to 6 in (10 to 15 cm) above the top of the casing is the floor, not the target. Below 4 in the bracket plate crowds the trim, the rings knock the casing when the panel is drawn, and rod and window read as one heavy horizontal object. Four inches is a mechanical minimum as much as a visual one: a typical bracket plate is 2 to 3 in (5 to 8 cm) tall and the ring drop eats another inch or two.
Halfway between the top of the casing and the ceiling is what most rooms want. On a 96 in (244 cm) wall with the casing topping out at 80 in (203 cm), the rod lands at 88 in (224 cm). There is a clean band of wall above the rod, the panels still frame the window rather than floating free of it, and a crown moulding keeps its own space.
2 to 4 in (5 to 10 cm) below the ceiling, or a ceiling-mounted track, is right whenever the casing-to-ceiling gap is under about 12 in (30 cm). At that point the halfway position is only 5 or 6 in above the trim, which satisfies nobody: too low to lift the room, too high to look tight. Commit to the ceiling instead. A rod tight to the ceiling reads as a decision; the same rod floating in the middle of a 6 in gap reads as a mistake.
Crown moulding is the common spoiler. The rod has to clear the bottom edge of the crown, and so does the bracket, which projects 3 to 5 in (8 to 13 cm) from the wall. A 5 in (13 cm) crown on a 96 in ceiling effectively drops your ceiling to 91 in (231 cm) for rod purposes. Either hang below the crown or fix a track to the ceiling inside it.
What height actually buys you#
The argument for hanging high is usually made in adjectives. It is better made in percentages.
The four hem positions#
| Hem | Gap at the floor | Where it belongs |
|---|---|---|
| Float | 1/2 in (1.3 cm) above | Everyday rooms, panels drawn daily, uneven floors, hems that cross a rug edge |
| Kiss | 0 | Flat level floors, still decorative panels, sheers under a working outer layer |
| Break | 1 in (2.5 cm) resting on the floor | Heavy linen, wool and velvet; formal rooms; panels rarely moved |
| Puddle | 3 to 6 in (8 to 15 cm) on the floor | Stationary decorative panels only. Not with pets, underfloor vents or daily use |
Float is the default and should be your assumption unless something argues against it. It gives the visual result of a full-length curtain with none of the maintenance, and the 1/2 in gap absorbs the floor variation described below. Kiss is the photograph hem: perfect in a new build on a level floor, unforgiving anywhere else, because a 1/4 in dip in the floor shows as a visible gap under one edge while the other edge folds.
Break borrows from tailoring and works for the same reason: a heavy cloth needs somewhere to land. It fails with lightweight cotton and linen, which crumple instead of breaking. Puddle is a period detail with a real cost, roughly 3 to 6 in of extra fabric per panel plus the labour of re-dressing it whenever it is disturbed.
Measure from the rod, and subtract the drop#
The single most common measuring error is taking the dimension from the top of the trim. The finished length you need is:
panel length = rod height above floor - hanging drop - floor gap
Hanging drop is the distance from the rod centre to the top of the hanging fabric, and it changes with the heading:
- Rings with clips: 1 to 2 in (2.5 to 5 cm) below the rod centre
- Rings with hooks in pleat tape: 3/4 to 1.5 in (2 to 4 cm)
- Ceiling track with hooks: 1/4 to 1/2 in (0.6 to 1.3 cm)
- Grommets or eyelets: negative. About 1 to 1.5 in (2.5 to 4 cm) of the panel sits above the rod, so the fabric hangs 2 to 3 in lower than the same panel on rings
- Rod pocket: negative by the height of the header flange, commonly 1 to 3 in (2.5 to 8 cm)
Ready-made lengths and the mid-wall trap#
Ready-made panels come in 84, 96, 108 and 120 in (213, 244, 274 and 305 cm). Wall heights and window positions do not come in 12 in steps, so the two rarely meet.
The trap is buying the length that fits and then hanging the rod to suit it. An 84 in panel with a 1.5 in ring drop and a float hem forces the rod to 86 in (218 cm). On a 96 in ceiling that leaves 10 in (25 cm) of bare wall above the rod: a band too wide to read as tight and too narrow to read as generous. The rod ends up mid-wall by accident, and the room loses the 8% it could have had.
Buy the next length up and hem it. Hemming a panel is 20 minutes with iron-on tape or an hour by hand, and it is the only variable in this whole exercise that you fully control.
| Ceiling | Casing top | Rod height | Finished length, float hem | Ready-made to buy |
|---|---|---|---|---|
| 96 in (8 ft / 2.44 m) | 80 in (203 cm) | 88 in (224 cm) | 86 in (218 cm) | 96 in, hem 10 in |
| 96 in (8 ft / 2.44 m) | 86 in (218 cm) | 93 in (236 cm) | 91 in (231 cm) | 96 in, hem 5 in |
| 108 in (9 ft / 2.74 m) | 84 in (213 cm) | 96 in (244 cm) | 94 in (239 cm) | 96 in, hem 2 in |
| 108 in (9 ft / 2.74 m) | 90 in (229 cm) | 99 in (251 cm) | 97 in (246 cm) | 108 in, hem 11 in |
| 120 in (10 ft / 3.05 m) | 90 in (229 cm) | 105 in (267 cm) | 103 in (262 cm) | 108 in, hem 5 in |
| 144 in (12 ft / 3.66 m) | 100 in (254 cm) | 122 in (310 cm) | 120 in (305 cm) | 120 in, no hem |
Rod heights assume a 1.5 in (4 cm) ring drop and a 1/2 in (1.3 cm) float. Row 2 uses the ceiling rule because the casing-to-ceiling gap is only 10 in. The curtain size calculator runs this arithmetic for your own casing height, and the width and fullness page handles the other axis.
When the floor is not the target#
Three things override floor length.
A radiator under the window. Hem to sill length, 1/2 in (1.3 cm) below the sill, or apron length, 4 in (10 cm) below the bottom of the apron, so the panel clears the radiator top by at least 2 in (5 cm). A floor-length panel in front of a radiator does measurable harm: it traps the convection plume between fabric and glass and vents a large share of that heat straight through the coldest surface in the room.
A window seat or a bench. The hem stops 1/2 in above the seat cushion or you will sit on it. If the seat runs past the window, treat the panels as stationary and hang them outside the seat entirely.
A deep sill you use. Kitchens and bathrooms with plants or bottles on the sill want sill or apron length for access, not drama.
Everywhere else, floor length wins. A short curtain on a wall with nothing under the window makes the window look stranded, and there is no compensating gain.
Floors that are not level#
Checking your own window in five minutes#
- Measure the casing top to the ceiling. Under 12 in (30 cm) sends you to a ceiling track; over 16 in (41 cm) sends you to the halfway rule.
- Mark the rod height on the wall in pencil and step back to the far side of the room. Look at the band of wall above the mark, not at the window.
- Measure floor to mark at the left bracket, the centre and the right bracket. Write down three numbers.
- Subtract your heading's hanging drop and the hem gap from each.
- Order the next ready-made length up, or give the three finished lengths to a fabricator.
If step 3 produces numbers that vary by more than 1/2 in (1.3 cm), hem each panel separately and use a float. If step 2 makes you uneasy, the mark is too low, not too high. Nobody has ever stood back and thought the rod was 2 in too close to the ceiling.
Frequently asked questions#
How high should you hang curtain rods?
Halfway between the top of the window casing and the ceiling, with an absolute minimum of 4 to 6 in (10 to 15 cm) above the casing. On a 96 in (244 cm) wall with the casing topping out at 80 in (203 cm), that puts the rod at 88 in (224 cm). If the gap from casing to ceiling is under 12 in (30 cm), stop splitting the difference and mount 2 to 4 in (5 to 10 cm) below the ceiling instead.
Should curtains touch the floor?
Usually they should just clear it. A float hem at 1/2 in (1.3 cm) above the floor is the safest choice: it reads as full length, it does not collect dust, and it hides up to about 1/2 in of floor level variation. A kiss hem at exactly 0 looks best in photographs and worst in old houses. A 1 in (2.5 cm) break suits heavy linen and velvet in rooms where the panels are rarely drawn.
What length curtains do I need for a 9 ft ceiling?
It depends on the rod height, not the ceiling. With a 108 in (274 cm) ceiling and the casing topping out at 84 in (213 cm), the halfway rod height is 96 in (244 cm). Subtract 1.5 in (4 cm) of ring drop and 1/2 in (1.3 cm) of float and the finished panel is 94 in (239 cm). Buy the 96 in ready-made and take 2 in off the hem.
Do you measure curtain length from the rod or the top of the window?
From the rod, always, and specifically from the point the fabric hangs from. With rings and clips that point is 1 to 2 in (2.5 to 5 cm) below the rod centre. With grommets the fabric sits about 1 to 1.5 in (2.5 to 4 cm) above the rod, so the same panel hangs 2 to 3 in lower. Measuring from the trim guarantees a short panel.
What curtain length works over a radiator?
Sill length, hemmed 1/2 in (1.3 cm) below the sill, or apron length ending 4 in (10 cm) below the apron. A floor-length panel in front of a radiator traps the convection current against the glass and pushes the heat straight out through the window. If the radiator sits under a window seat, the seat sets the same limit for a different reason.
Can curtains be too long?
Yes, in two ways. Anything past a 1 in (2.5 cm) break becomes a puddle, and a puddle has to be re-dressed by hand every time someone walks past it. And a panel that is long because the rod is low wastes the whole point: the extra fabric is at the bottom, where nobody reads it, instead of at the top where it lifts the eye.
How far above the window should the rod go in a room with low ceilings?
As high as the ceiling allows. In a room with a 7 ft 6 in (2.29 m) ceiling and a casing at 82 in (208 cm), you have 8 in (20 cm) to play with, so use a slim ceiling-mounted track or a rod 2 in (5 cm) below the ceiling. Low rooms are exactly where the height gain matters most, because the percentage gain on a short wall is larger.
Sources and standards referenced#
- The Encyclopaedia of Curtains Merrick and DayHeading drops, hook and ring allowances, finished length conventions
- Curtain Design Directory Merrick and DaySill, apron and floor length conventions
- Interior Graphic Standards WileyWindow casing and sill heights, head detail dimensions
- Architects' Data Ernst Neufert, WileyTypical window head and sill heights relative to floor and ceiling
- Human Dimension and Interior Space Panero and Zelnik, Whitney Library of DesignStanding reach limits used for rod and track access
We cite published codes, industry planning guidelines and manufacturer specifications. Where a figure is our own recommendation rather than a published standard, the text says so. See how we measure.