Why this pair matters
Moving from UK Double to King changes both width and length: 15 cm wider and 10 cm longer.
The figures above are calculated from the identified dimensional records, not from rounded display conversions.
UK Double is 15.0 cm narrower and 10.0 cm shorter than UK King.
The calculated surface-area difference is 14.5%, measured relative to UK King.
Width A − B-15.0 cm
Length A − B-10.0 cm
Area A − B-14.5%
Dimensions side by side
Compatibility decision
The extra length is as important as the width when checking a bedstead or fitted sheet.
Rigid frames, enclosed bases, fitted sheets and protectors should be selected from finished product measurements and depth—not from the closest name.
Check the underlying records
Review UK Double dimensions and tolerance · Review UK King dimensions and tolerance · Compare another country-qualified pair · Measure before buying
Evidence for this answer
- Dreams — The bed and mattress size guideChecked 27 August 2026. Retailer evidence used for dimensions and naming only.
- Which? — UK bed sizes: bed and mattress size guideChecked 27 August 2026. Independent corroboration; no protected prose, tables or imagery reproduced.
Correction route: If a current source or product specification conflicts with this page, send the page URL and evidence through the corrections process.