54" X 75"
Depends. They vary in weight.
The mattress on my day bed is 37"X74".
38" x 75"
Queen - 60×80 in (152x203 cm) | 160×200 cm (63.0x78.7 in) in the E.U. Also... Olympic/Expanded Queen novelty size by Simmons - 66×80 in (167×203 cm) California Queen (primarily a wood-framed...