Curtain Lights Size Guide: How to Measure, LED Density and 3m x 3m Sets

The most common curtain light regret isn't the color or the effects. It's the size: a set that stops a foot short of the frame, or one that piles up on the floor and hides half the picture. Ten minutes with a tape measure prevents both.

This curtain lights size guide shows you how to measure, what the usual sizes look like in real rooms, why LED density matters as much as width, and how many sets a wide window or balcony needs. It finishes with a straight answer on which Lumalyn size to pick.

Disclosure: CurtainLights is affiliated with Lumalyn and may earn a commission if you buy through our links.

How to measure in five minutes

1. Choose the mounting line. Decide where the top cable will hang: the top of the frame, a curtain rod, ceiling hooks or the underside of the balcony above.
2. Measure the width along that line, not across the glass. If the hooks sit outside the frame, measure hook to hook.
3. Measure the drop from the mounting line to where the strands should end: the sill, the floor or the top of a glass railing. Leave about 2 in (5 cm) so strands don't drag.
4. Note obstacles: handles, hinges, blinds, a door that swings into the space.
5. Find the power. Measure the distance from the curtain's top corner to the nearest outlet. Lumalyn doesn't list its USB cable length, so if the outlet is far away, plan for a power bank or a USB extension cable kept indoors or dry.
6. Write it down in both units, since sets are often sold in meters.

Common curtain light sizes, from 1 × 1 m to 3 × 3 m

Curtain sets are usually listed as width × drop in meters. Sizes you'll often see:

Size (W × H)	In feet	Area	Typical fit
1 × 1 m	3 ft 3 in × 3 ft 3 in	11 sq ft	Small window, mirror, desk wall
1.5 × 1.5 m	4 ft 11 in × 4 ft 11 in	24 sq ft	Average window, headboard
2 × 2 m	6 ft 7 in × 6 ft 7 in	43 sq ft	Large window, glass door, headboard wall
3 × 2 m	9 ft 10 in × 6 ft 7 in	65 sq ft	Wide window, party wall
3 × 3 m	9 ft 10 in × 9 ft 10 in	97 sq ft	Tall glass, high ceilings, event backdrops

Lumalyn's animated curtain comes in the two square sizes: 2 × 2 m and 3 × 3 m.

LED density: the number most size charts skip

Width tells you what a curtain covers. Density tells you how good it looks. On a plain glow curtain, it mostly affects brightness. On a pixel curtain, which draws pictures and text, it decides how sharp those pictures are.

Lumalyn makes the trade-off easy to see, because both sizes have the same 400 LEDs:

Lumalyn size	LEDs	Per sq ft	Per m²
6 ft 7 in square (2 × 2 m)	400	about 9	about 100
9 ft 10 in square (3 × 3 m)	400	about 4	about 44

On paper, the 2 m set is more than twice as dense. That matters most up close: inside a room, or on a balcony people see from just a few steps away. From across a street, the gaps between pixels are harder to notice, so the bigger set's spread can work well there. Our LED curtain lights guide explains plain vs. pixel curtains in more detail.

Typical window, door and balcony sizes

Every home is different, so treat these as starting points and measure yours.

Opening	Often about	Size to consider
Glass balcony door or French doors	5–6 ft (1.5–1.8 m) wide, 6 ft 8 in (2 m) tall	2 × 2 m
Sliding patio door	6 or 8 ft (1.8 or 2.4 m) wide, 6 ft 8 in (2 m) tall	2 × 2 m; 3 × 3 m only with room above
Room ceiling height	8–9 ft (2.4–2.7 m)	2 × 2 m drop fits; 3 × 3 m drop is longer
Balcony railing	3–3 ft 6 in (0.9–1.1 m) high	Hang from above, not from the rail
Single window	Varies widely	2 × 2 m on a rod, or a smaller plain set

Two points trip people up. First, a railing is far shorter than any curtain's drop, so clipping a 6 ft 7 in curtain to the rail leaves a pile of strands at the bottom. Hanging it from the ceiling or the balcony above lets it fall straight to the floor, which looks better and shows the full design through glass railings.

Second, a curtain wider than a small window isn't a problem if you mount it on a rod that runs past the frame or spans a pair of windows. For window-specific tips, see our window curtain lights guide.

3m x 3m curtain lights: when the big size makes sense

A 3m x 3m curtain is impressive, but it's not the default choice. It's 9 ft 10 in tall, so in a room or balcony with an 8 to 9 ft ceiling, the bottom 1–2 ft will rest on the floor. On a plain curtain that's fine. On a pixel curtain, the bunched rows hide part of every picture.

Choose 3 × 3 m when you have:

• double-height windows, lofts or ceilings of about 10 ft (3 m) or more;
• a wide sliding door or glass wall where coverage matters more than crisp detail;
• an event backdrop hung from a beam or stand;
• an audience that mostly sees it from a distance, like a street below.

Otherwise, the 2 × 2 m set fits more homes and gives the sharper image.

How many sets do you need?

Divide the width to fill by the curtain width. Round up for edge-to-edge coverage, or round down if small gaps between sets are fine.

Width to fill	2 m sets	3 m sets
6 ft 7 in (2 m)	1	1 (overhangs)
10 ft (3 m)	1–2	1
13 ft (4 m)	2	1–2
16 ft 5 in (5 m)	2–3	2
20 ft (6 m)	3	2
26 ft (8 m)	4	3

Each Lumalyn set comes with its own USB controller, and the listing doesn't describe linking curtains into one big picture. Plan on each set running its own scene; picking the same or matching scenes can still look coordinated. Lumalyn takes 10% off two sets and 20% off three.

When the size isn't exact

• Slightly too wide: use a rod that extends past the frame, or center the curtain and let the edges overlap the wall.
• Slightly too long: raise the mounting line, or let the bottom rest on the sill or floor. Looping extra length over the rod works for plain curtains but hides rows on a pixel curtain.
• Too short: mount it higher, from ceiling hooks or the balcony above.
• Windows that open: keep handles and hinges clear so you can still use them.

Which Lumalyn size should you choose?

Pick 6 ft 7 in (2 × 2 m) if…	Pick 9 ft 10 in (3 × 3 m) if…
your space is up to about 6 ft 7 in wide	your space is about 8–10 ft wide
your ceiling is a standard 8–9 ft	you have about 10 ft of height, or don't mind extra on the floor
you want the sharpest pictures and text	coverage matters more than detail
people see it up close	people see it mostly from a distance

For most windows, glass doors and standard balconies, we'd choose the 2 × 2 m set.

Whichever size you pick, you get the same features: 400 individually controlled LEDs, 100+ scenes, DIY drawing and scrolling text, 5 music-sync modes, a timer, Bluetooth app and remote control, and 5 V USB power (adapter not included). It's IP44, so keep it indoors or in a sheltered outdoor spot; our outdoor curtain lights guide explains what that means.

Shipping is free and tracked worldwide, with dispatch in 1–3 business days and delivery in about 7–12. Returns are free within 30 days, though Lumalyn's refund policy asks for items to be unused and complete in the original packaging, which is one more reason to measure first. A 2-year warranty covers faults. Import duties may apply, and for Christmas, order by December 10.

Tape measure done? Choose your Lumalyn size.