We mention sizes in terms of the name (Twin, Full, etc.). Here are the actual standard sizes in inches: - Twin Size Mattress 38" x 75" - Twin XL Mattress 38" x 80" - Full Size Mattress 54" x 75" - Queen Size Mattress 60" x 80" - King Size Mattress 76" x 80" - California King Size Mattress 72" x 84"