King vs. California King: Size Comparison Guide [2026] - Purple California king mattresses measure 72 inches wide and 84 inches long — 4 inches longer and 4 inches narrower than a king This variation of the standard king is widely available, making it the longest standard size mattress on the market
King vs. California King: Whats the Difference? - Zoma Size Difference: The main distinction between a king and a California king mattress is their dimensions A king mattress is 4 inches wider, while a California king is 4 inches longer, making the choice dependent on whether you prioritize width or length