How to Choose Curtains: Size, Fabric and Hanging Guide (2026)

By Saad · Published 3 November 2026 · Updated 6 November 2026 · 9 min read · Curated Home Stories

Quick answer: Choose curtains by measuring the window, then hanging the rod high and wide. The rod should be 15 to 20 cm above the window and extend 15 to 20 cm beyond each side. The curtain length should just touch the floor, and the fullness should be 1.5 to 2 times the rod width.

Curtains do more than block light. They make a window look larger, a room look taller, and a space feel finished. The wrong curtains, too short, too narrow, or hung too low, make a room look smaller and cheaper. The right curtains, hung high and wide, make the same room look taller and more expensive. This guide explains how to measure, choose and hang curtains, with the numbers that matter.

Measure the window and the rod

Measure the window width, from the outside of the frame, and the height from the floor to the top of the window. The curtain rod should be 15 to 20 cm (6 to 8 inches) above the top of the window frame, and it should extend 15 to 20 cm beyond each side of the window, so the curtains can be pulled clear of the glass. This makes the window look larger and lets in more light. Measure the rod length, not the window width, when you calculate the curtain fullness, because the curtains must cover the rod, not just the window. Our curtain calculator works out the width and length for your window.

Try the curtain calculator.

Curtain length: floor, sill or puddle

Curtain length depends on the room and the style. Floor-length curtains, which just touch the floor or hover 1 to 2 cm above it, suit living rooms and bedrooms, because they make the room look taller. Sill-length curtains, which end at the windowsill, suit kitchens and bathrooms, where floor-length curtains would get wet or dirty. Puddled curtains, which pool on the floor, suit a formal, romantic room, but they are hard to clean and can trip people. For most rooms, floor-length curtains that just touch the floor are the best choice, because they look clean and make the room feel taller.

Fullness: how wide should curtains be?

Curtains need fullness to look good. Fullness is the ratio of the curtain fabric width to the rod width, and it should be 1.5 to 2 times the rod width for a full, gathered look. A fullness of 1.5 is suitable for a sheer or light fabric, and a fullness of 2 is suitable for a heavy fabric or a formal room. A curtain with no fullness, where the fabric is the same width as the rod, looks flat and cheap when closed, and it does not cover the window properly. Measure the rod, multiply by 1.5 to 2, and buy curtains that total that width. If you are buying ready-made curtains, buy two panels, not one, so the fullness is correct.

Fabric and lining

Curtain fabric affects how the curtains hang, how they block light, and how they feel. Linen and cotton hang naturally and suit a relaxed, casual room. Velvet and heavy cotton hang well and suit a formal room, and they block light and sound. Sheer fabrics let light in and suit a room where privacy is not a concern. Lining is important: a lined curtain hangs better, blocks more light, and protects the fabric from sun damage. Blackout lining blocks almost all light and suits a bedroom. Thermal lining helps keep a room warm in winter and cool in summer. Choose a fabric and a lining that suit the room and the light.

Hanging curtains high and wide

Hang the curtain rod high and wide, 15 to 20 cm above the window and 15 to 20 cm beyond each side, so the window looks larger and the room looks taller. Use a rod that is strong enough for the weight of the curtains, and use brackets that are fixed securely into the wall. Hang the curtains so they just touch the floor, and use a hem that is even. If the curtains are too short, they will make the room look smaller. If the rod is too low, the window will look smaller. Hanging curtains high and wide is the single most effective trick for making a room look taller, and it costs nothing.

Curtain styles and headings

Curtain headings affect how the curtains hang and how they look. A pencil pleat heading is versatile and suits most rooms. An eyelet heading is modern and easy to open and close, and it suits a contemporary room. A tab top heading is casual and suits a relaxed room. A pinch pleat heading is formal and suits a traditional room. Choose a heading that suits the style of the room, and use the same heading throughout the home, so the curtains feel consistent. Avoid a heading that is too fussy for the room, because it will draw attention to itself rather than to the window.

Curtains for different rooms

Living room curtains should be floor-length, with a fullness of 1.5 to 2, and a fabric that suits the room. Bedroom curtains should be blackout-lined, so the room stays dark, and floor-length, so the room feels tall. Kitchen curtains should be sill-length, in a washable fabric, so they do not get wet or dirty. Bathroom curtains should be short, light and washable, or use a blind instead. A curtain that suits the room is a curtain that works, and a curtain that does not suit the room will be a problem every day.

Curtain mistakes to avoid

The most common mistakes are curtains that are too short, too narrow, or hung too low. Other mistakes are a rod that is too short, so the curtains cover the window when open, a fabric that is too heavy for the rod, and no lining, so the curtains do not hang well and do not block light. Fix the length, the fullness and the hanging height first, because they define how the curtains look. Curtains that are hung high and wide, with the right fullness and length, make a room look taller and more expensive, while curtains that are too short and too narrow make a room look smaller and cheaper.

Key measurements at a glance

These are the standard measurements used by designers for a room like this. They are the same figures used throughout this guide, collected here so you can check them at a glance while you plan.

5 mistakes to avoid

1. Choosing paint from a tiny swatch instead of a large sample.
2. Skipping primer on a dark wall, which wastes paint and leaves patchy colour.
3. One thick coat of paint instead of two thin coats.
4. Hanging a gallery wall without planning the layout on the floor first.
5. Starting electrical, gas, plumbing or structural work without a professional.

Note: measurements and spacing guidance in this article are general design guidance for typical homes, in imperial and metric. Check manufacturer instructions and local building regulations for your specific project, especially for electrical, plumbing and structural work.

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