Here's Wikipedia's supposed bed standards for the US. Ones in bold are ones I've slept on in hotels:

Small Double or Three-quarter 48 in × 75 in

Double or Full 54 in × 75 in

Double Extra Long 54 in × 80 in

Queen 60 in × 80 in

Expanded, Super or Olympic Queen 66 in × 80 in

King 76 in × 80 in

California King or King Long 72 in × 84 in

Grand King or Super King or Texas King 80 in × 98 in