Mattress Size Guide
Asquith Mattresses
Mattress Size Guide
Choosing the right mattress size is essential for comfort, support and making the most of your bedroom space. All Asquith mattresses are made to standard UK sizing for a reliable fit across most bed frames and bases.
Use the guide below to compare dimensions in feet & inches and centimetres.
UK Mattress Sizes & Dimensions
Single Mattress (3FT)
Width: 3’0” (90cm)
Length: 6’3” (190cm)
Ideal for children, teenagers, guest rooms, or smaller bedrooms.
Small Double Mattress (4FT)
Width: 4’0” (120cm)
Length: 6’3” (190cm)
A space-saving option for solo sleepers who want extra room, or compact double bedrooms.
Double Mattress (4FT6)
Width: 4’6” (135cm)
Length: 6’3” (190cm)
The most popular UK mattress size, suitable for couples or individuals who enjoy more sleeping space.
King Size Mattress (5FT)
Width: 5’0” (150cm)
Length: 6’6” (200cm)
Perfect for couples who want extra width and more freedom of movement during sleep.
Super King Size Mattress (6FT)
Width: 6’0” (180cm)
Length: 6’6” (200cm)
Our most spacious option, offering maximum comfort and room to stretch out.
Which Size Is Right for You?
How to choose the right size
When choosing your mattress size, consider:
• The size of your bedroom and available floor space
• Whether you sleep alone or with a partner
• Your height and preferred sleeping space
• Your existing bed frame dimensions
All Asquith mattresses are made to standard UK sizing for compatibility across most bed frames and bases.