What Size Silk Pillowcase Do You Need? UK vs USA Sizing Guide
By The Lunelle Team | June 2026 | Silk Education, Buying Guides
The short answer
UK Standard pillowcases measure 50x75cm (20 by 30 inches), which is the same as a US Queen. US Standard pillowcases (20 by 26 inches) are shorter than UK Standard, so if you are shopping across borders, always check the dimensions in centimetres or inches rather than the size name alone.
In this guide
- UK silk pillowcase sizes explained
- US silk pillowcase sizes explained
- UK vs US size comparison table
- Which size should you buy?
- How to measure your pillow
- Does the fit affect how silk works?
- Frequently asked questions
What are the standard silk pillowcase sizes in the UK?
There are three main pillow sizes used in British bedrooms, and pillowcases are made to match.
| UK Size | Dimensions (cm) | Dimensions (inches) |
|---|---|---|
| Standard | 50 x 75 cm | 20 x 30 in |
| King | 50 x 90 cm | 20 x 36 in |
| Square / European | 65 x 65 cm | 26 x 26 in |
The standard size fits most British pillows and is by far the most common. King size suits the longer bolster-style pillows you find on super-king beds. Square pillowcases are used for decorative cushions or on continental-style bolsters.
If you are unsure which you have, measure your pillow while it is lying flat. Most households in the UK will need a Standard pillowcase.
What are the standard silk pillowcase sizes in the USA?
American beds typically use more pillow sizes than their British counterparts, with four common options.
| US Size | Dimensions (inches) | Dimensions (cm) |
|---|---|---|
| Standard | 20 x 26 in | 51 x 66 cm |
| Queen | 20 x 30 in | 51 x 76 cm |
| King | 20 x 36 in | 51 x 91 cm |
| Body | 20 x 54 in | 51 x 137 cm |
The US Standard is noticeably shorter than most British pillows. US Queen is the size that UK shoppers will recognise as their Standard. US King matches the UK King almost exactly.
Always measure your pillow flat before buying. The size name alone can be misleading across borders.
What is the difference between UK and US silk pillowcase sizes?
The names do not match up, and this catches a lot of people out. Here is a side-by-side view of how UK and US sizes correspond to each other.
| UK Size | UK Dimensions | US Equivalent | US Dimensions |
|---|---|---|---|
| Standard | 50 x 75 cm | Queen | 51 x 76 cm |
| King | 50 x 90 cm | King | 51 x 91 cm |
| Square | 65 x 65 cm | No direct match | Euro (66 x 66 cm) |
The biggest trap: a UK shopper ordering from a US brand and selecting Standard will receive a pillowcase that is 9cm shorter than their pillow. The pillow will poke out of the end. To avoid this, a UK buyer shopping a US brand should order Queen size.
Set of 2. Available in Standard, Queen, and King. Grade A 100% pure mulberry silk. Envelope enclosure. The best everyday silk bedding for hair and skin.
Which size silk pillowcase should I buy?
Start by identifying what country your pillow is from, then match accordingly.
If you are in the UK and buying from a UK brand, select Standard for most pillows, King for longer pillows on a super-king bed, or Square for decorative cushions.
If you are in the UK and buying from a US brand, select Queen (not Standard). This matches the dimensions of a UK Standard pillow.
If you are in the US and buying from a UK brand, select Standard on the UK site. This will correspond to a US Queen in size.
When in doubt, skip the size name entirely and check the dimensions in centimetres or inches. A pillowcase should be at least 2.5cm smaller than your pillow on each side for a snug, tuck-free fit.
How do I measure my pillow to find the right pillowcase size?
Lay your pillow flat on a table. Measure the width (across the short side) and the length (across the long side) with a tape measure. Write both dimensions down.
Then compare against the tables above. If your pillow measures 50 x 75cm, you want a UK Standard or a US Queen. If it measures 50 x 90cm, you want a UK King or a US King.
One tip: measure in the morning after the pillow has been fluffed. A compressed pillow can measure up to 2cm shorter than its true size.
Does the size of a silk pillowcase affect how it works for your hair and skin?
Yes, it does. A pillowcase that is too loose will bunch and fold during the night. Those folds press against your face and hair in the same way a regular cotton case would, which reduces the benefit of the smooth silk surface.
A pillowcase that is too tight puts strain on the seams. With silk, that strain can cause pilling or wear at the edges over time.
The right fit means the silk lies flat and stays flat, so your skin and hair glide across a smooth, uninterrupted surface all night.
A well-fitted silk pillowcase lies flat and smooth throughout the night, maximising the benefit for your hair and skin.
Frequently asked questions
Is a UK Standard pillowcase the same as a US Standard?
No. A UK Standard pillowcase measures 50x75cm (20x30 inches), while a US Standard measures 51x66cm (20x26 inches). The UK Standard is 9cm longer. If you are shopping a US brand for a UK pillow, you need to order Queen size.
What size silk pillowcase fits a standard UK pillow?
A UK Standard pillowcase (50x75cm) fits most standard UK pillows. If your pillow is longer, typically 50x90cm, you need a King size pillowcase instead.
Can I use a US Queen silk pillowcase on a UK Standard pillow?
Yes. A US Queen (51x76cm) and a UK Standard (50x75cm) are virtually identical in size, with only 1cm difference in length. Either will fit a UK Standard pillow comfortably.
Does a silk pillowcase need to be a tight fit?
Not tight, but snug. The pillowcase should be slightly smaller than the pillow so it sits flat and does not bunch. Most pillowcases are designed with a small negative ease built in. If the case is too loose, the fabric will fold and press against your skin, reducing the anti-friction benefit of silk.
What momme weight silk pillowcase should I choose?
22 momme is the best choice for most people. It is smooth, durable, and comfortable year-round. 30 momme is heavier and denser, with a more luxurious drape and longer lifespan. Both are available in Standard, Queen, and King size.
Set of 2. Available in Standard, Queen, and King. Grade A 100% pure mulberry silk with envelope enclosure. Heavier, denser, and built to last for years.