Standard UK curtain sizes

Ready-made curtains in the UK are sold in four drops — 137, 183, 228 and 274 cm, which are the imperial 54, 72, 90 and 108 inches rounded — and in four widths per curtain: 117, 167, 228 and 297 cm. The width on the packet is the width of each curtain flat, not the width of window the pair covers, which is why a “167 cm pair” suits a track of roughly 130 cm and no more. None of these sizes is a standard in any formal sense; they are trade conventions, and the metric label is always a rounded imperial figure.

The four ready-made drops

The drop is the vertical measurement, and it is the one the trade quotes first. Four sizes cover almost everything sold in the UK. They are imperial sizes underneath, which is why the metric labels are not round numbers.

Measure the drop from the hook, ring or eyelet position — not from the top of the pole, and not from the ceiling. On a pole hung with rings the hook sits two or three centimetres below the pole itself, so a curtain hangs lower than the pole height suggests. On a track the difference is smaller but still there. Getting this wrong by the depth of a ring is how a floor-length curtain ends up resting on the carpet in a heap.

The three shorter drops are compromises around a windowsill. 137 cm finishes at or just above a sill on a typical UK window; 183 cm clears the sill and stops short of the floor, which is the length most rooms end up with; 228 cm reaches the floor under a standard 2.4 m ceiling. The fourth, 274 cm, exists for high ceilings, Victorian bays and rooms where the pole is fitted close to the cornice.

The four ready-made widths, and the number everyone misreads

The width on the packet is the width of each curtain, flat. It is not the width of window the pair will cover, and it is not the two curtains added together. A pair labelled 167 cm contains two panels of 167 cm each — about 335 cm of cloth in total — which is why it suits a track of roughly 130 cm and looks mean on anything wider.

What each width actually gathers to

Fullness is the ratio between the flat cloth in a curtain and the track it covers, and it is the thing a packet cannot tell you, because it depends on your window rather than on the curtain. The table below runs every ready-made width against a range of track widths using the same function the curtain fullness calculator uses for its achieved-fullness figure.

Read down a column rather than across a row. On a 180 cm track, the 167 cm pair gathers to about 1.9× — acceptable for an eyelet heading, marginal for a pencil pleat — and the 228 cm pair gives a comfortable 2.5×. On a 260 cm track only the widest pair still clears 2×; the 228 cm pair drops to 1.76×, which an eyelet heading carries and a pencil pleat does not.

A pencil pleat wants 2× as a floor and hangs better nearer 2.5×. Eyelet and tab-top headings are designed to work from about 1.5–1.8×, because the fabric falls in waves rather than gathers. That difference is why the same pair can look generous on one heading and skimped on another, and the heading entry in the glossary sets out what each style consumes.

Why the metric sizes are such odd numbers

Every metric figure on this page is a rounded imperial one. 54 inches is 137.16 cm and is printed as 137. 90 inches is 228.6 cm and is printed as 228. The trade set these sizes in imperial and never re-cut them when the labels changed, so the metric number on the packet has always been a conversion rather than a measurement.

For a ready-made curtain the rounding is harmless — half a centimetre on a hem nobody measures. It stops being harmless when the same habit is applied to roll widths, where a fabric sold as 54 inch is 137.16 cm and a fabric sold as 140 cm really is 140, and the two get used interchangeably. Over four joined widths that gap is more than a centimetre of finished width per seam. The fabric width converter keeps the two apart.

When ready-made stops making sense

Three situations, and the arithmetic above shows all of them. Past a track of about 230 cm the second-widest pair falls below 2×, so the widest size becomes the only one that gathers on a pleated heading — and above roughly 290 cm even that runs out. A drop that falls between two sizes wastes either length or money — go up rather than down, because a curtain slightly too long can be hemmed and one slightly too short cannot be fixed. And a bay or a window with an awkward return needs a width the shelf does not carry.

At that point making up your own is usually cheaper than the alteration, and it is the only way to get the fullness you actually want rather than the fullness the nearest packet happens to give. The curtain fabric calculator works out the cloth from your track width and drop, including the pattern repeat if the fabric has one, and shows every allowance it adds.

These sizes are conventions rather than standards. No British Standard fixes them, individual retailers stock subsets, and the wide end in particular varies from shop to shop. Treat the tables as what to plan around, and measure the curtain you are actually buying.

Common questions

Does the curtain width on the packet mean the width of my window?

No, and this is the mistake that costs people a return. The figure is the width of each curtain, flat. A pair labelled 167 cm contains 334 cm of cloth in total, which gathers to cover a track of about 130 cm at a reasonable fullness. Buying to match your track width gives curtains that barely close.

Where is the drop measured from?

From the hook, ring or eyelet position down to where you want the hem to finish — not from the top of the pole and not from the ceiling. On a pole with rings the hook sits below the pole, so the curtain hangs lower than the pole height; on a track it sits close to the track itself.

Why are the metric sizes such odd numbers?

Because they are imperial sizes wearing metric labels. 54 inches is 137.16 cm and gets printed as 137; 90 inches is 228.6 cm and gets printed as 228. The trade never re-cut its sizes when the labels changed, so every metric ready-made figure on the shelf is a rounded conversion of an older imperial one.

What if my window falls between two ready-made sizes?

Go up rather than down. A curtain slightly too long can be hemmed or allowed to break on the floor; one slightly too short looks wrong and cannot be fixed. If the gap is large in either direction, making up your own is usually cheaper than the alteration, and the calculators here work out the cloth.

Are these sizes an actual British Standard?

No. There is no standard fixing ready-made curtain sizes, and individual retailers do sell sizes outside this list — particularly at the wide end for patio doors. These are the four drops and four widths that are common enough to be worth planning around, and any given shop may stock a subset.

Related tools

Curtain fabric calculator

Track width, drop, fullness and pattern repeat in; metres or yards to buy out, with every allowance adjustable.

Curtain fullness calculator

How many widths each curtain needs at the fullness you want — and what whole widths really gather to.

Pattern repeat calculator

The cut length a repeat forces, what is trimmed from every piece, and what matching the design costs.

Fabric width converter

Pattern written for one bolt width, fabric bought at another — work out the equivalent length.

Updated 20 August 2026 · Method v1 · Written and maintained by Wickeey · Tell me if a result looks wrong