Here are some common mattress sizes in the United States. I hope they will be helpful to you.

1-- Single or Twin Size: 39x75 inch or 99x190.5cm;

2-- Twin XL Size: 39x80 inch or 99x203cm;

3-- Double Size: 54x75 inch or 137x190.5cm;

4-- Queen Size: 60x80 inch or 153x203cm;

5-- King Size: 76x80 inch or 193x203cm;

6-- California King Size: 72x84 inch or 183x213cm;