Mattress Size Chart: US and UK Sizes in Inches and Centimetres

Mattress names mean different things in different countries. A "double" in the UK is not the same as a "double" in the US, and a "king" is a different size again. Use these charts to compare sizes, then measure your own frame before you order.

US mattress sizes

UK mattress sizes

Some UK and European sellers also offer a long single (90 × 200 cm) and other sizes. Check the exact dimensions on the product page rather than relying on the name.

Comparing US and UK sizes

• A UK king (150 × 200 cm) and a US queen (about 152 × 203 cm) are very close in size, but a US king is far wider.
• A UK double is slightly narrower than a US full, and both are tight for two adults.
• A US king (193 cm wide) is a little wider than a UK super king (180 cm).
• Sheets, covers and bed frames are sold to match their own country's sizes. Check that a bed frame and mattress come from the same system.

Sizes vary by a centimetre or two between manufacturers, so treat these charts as typical rather than exact.

How to measure for a mattress

1. Measure your bed frame, not your old mattress. Mattresses compress and shift over time, and your old one may not have been the right size.
2. Measure the inside of the frame from side to side and head to foot, at more than one point, since frames can be slightly out of square.
3. Measure the frame's depth (the height of the sides above the slats or base) if it has a rim, so the mattress doesn't sit too high or too low.
4. Allow for a snug fit. A small gap, around a centimetre or half an inch, is normal. Avoid a mattress that is noticeably smaller or larger than the frame.
5. Check the base. Slatted bases need slats spaced according to the mattress maker's guidance, and some mattresses need a solid or sprung base.

Depth, sheets and weight

• Mattress height commonly ranges from about 6 to 14 inches (15 to 35 cm). Fitted sheets list the depth of mattress they fit, so check it against a thick mattress or a topper. Our guide to bedding and mattress toppers covers that.
• Weight and handling. Large mattresses are heavy and bulky. Check stairs, hallways and doorways, as explained in our guide to buying furniture online.
• Boxed and rolled mattresses arrive compressed and need time to expand. Follow the maker's instructions.

Cot and crib mattresses

Cot and crib mattresses must fit the cot closely, and safety standards apply. In the US, federal rules set minimum dimensions and a maximum thickness for full-size crib mattresses. In the UK, common cot sizes are around 120 × 60 cm and cot bed sizes around 140 × 70 cm. Follow the cot maker's stated mattress size, and avoid any gap around the edges that a child could be trapped in. Check the current safety rules in your country before buying.

Returns and trial periods

Many online mattress sellers offer a trial period, but read the conditions: some require you to keep the mattress for a minimum number of weeks before returning it, some charge for collection, and some only accept returns of mattresses in good condition with the original protector. See our guide to refunds and chargebacks for what to do if a seller doesn't follow its own policy.