Choosing a Bed Frame: Mattress Size, Outer Dimensions and Height

A bed’s mattress size is only part of its footprint. Side rails, a curved footboard or tall posts can make the frame substantially larger. Begin with your mattress dimensions, then measure the room for the complete frame and the space needed beside it.

Compare the complete frame

The two king examples accommodate the same stated 150 × 200 cm mattress size but have different external dimensions. In a 320 cm-wide illustrative room, a centred 168 cm frame leaves 76 cm on each side before bedside furniture is added. Measure your actual skirting, radiators and doors as well.

Look above and below the mattress

A lower frame can give a different view across the room from a tall headboard or posts. Check window positions, sloping ceilings and nearby lights. Under-bed clearance is not always the same as usable storage height: the Craft listing distinguishes its leg height from its 15 cm storage clearance.

Confirm the delivered specification

Check the exact mattress size required, whether the mattress is included, the support system and the assembly instructions. The Craft listing requires assembly. Ask for package dimensions where access is tight; the assembled width alone will not establish whether boxes can reach the bedroom.

Browse bed frames or read our four-poster planning guide for the extra measurements a tall bed needs.

Choosing a separate headboard? Our wall-mounted headboard guide explains how to compare its width, lower opening and position above the mattress.