Bed, Mattress and Sheeting Sizes 101

• Mattress Sizes
  
  • Twin--39 x 75 inches (or 99 x 190 cm)
  • X-Long Twin--39 x 80 inches (99 x 203 cm)
  • Full--54 x 75 inches (137 x 190 cm)
  • Queen--60 x 80 inches (or 153 x 203 cm)
  • King--76 x 80 inches (or 198 x 203 cm)
  • California King--72 x 84 inches (or 182 x 213 cm)
  
  
• Fitted Sheet Sizes
  
  • Twin--39 x 75 inches (or 99 x 190 cm)
  • X-Long Twin--39 x 80 inches (99 x 203 cm)
  • Full--54 x 75 inches (137 x 190 cm)
  • Queen--60 x 80 inches (or 153 x 203 cm)
  • King--76 x 80 inches (or 198 x 203 cm)
  • California King--72 x 84 inches (or 182 x 213 cm)
  
  
• Flat Sheet Sizes
  
  • Twin--66 x 96 inches (or 167 x 243 cm)
  • X-Long Twin--66 x 102 inches (or 167 x 259 cm)
  • Full--81 x 96 inches (or 205 x 243 cm)
  • Queen--90 x 102 inches (or 228 x 259 cm)
  • King/California King--108 x 102 inches (or 274 x 259 cm)
  
  
• Comforter Sizes
  
  • Twin--68 x 86 inches (or 173 x 218 cm)
  • Full/Queen--86 x 86 inches (or 218 x 218 cm)
  • King/California King--100 x 90 inches (or 254 x 229 cm)

Source: About.com http://interiordec.about.com/od/beds/a/bedsizes.htm