A fitted sheet for a standard king size bed measures 76 by 80 inches, while a flat sheet measures 108 by 102 inches. A California king size bed uses a fitted sheet that is 72 by 84 inches and a flat sheet that is 108 by 102 inches.
A standard king size mattress measures 76 by 80 inches, which is the same length as a standard queen size bed, but 16 inches wider. A California king size mattress is only 12 inches wider than a standard queen size bed, but adds four inches in length. The California king, or Western king, is the longest mattress size available.