<P> Standard bed sizes are based on standard mattress sizes, which vary from country to country . Bed sizes also vary according to the size and degree of ornamentation of the bed frame . Dimensions and names vary considerably around the world, with most countries having their own standards and terminology . In addition, two mattresses with the same nominal size may still have slightly different dimensions, due to manufacturing tolerances, amount of padding, and support type . </P> <P> Modern manufacturing conventions have produced many standard mattress and box spring sizes . Beds vary by country of origin as per the table below . These dimensions are for the mattress--actual bed frames are a little larger to accommodate the mattress . Mattress thickness varies considerably . </P> <Table> Mattress size (width × length) <Tr> <Th> </Th> <Th> US and Canada </Th> <Th> Australia </Th> <Th> Ireland and UK </Th> <Th> New Zealand </Th> <Th> Continental Europe </Th> <Th> Scandinavia </Th> <Th> Japan </Th> <Th> China </Th> <Th> Thailand </Th> <Th> Singapore </Th> <Th> Brazil </Th> </Tr> <Tr> <Th> Small single or Cot </Th> <Td> 30 in × 75 in 76 cm × 191 cm </Td> <Td> </Td> <Td> 60 cm × 190 cm 24 in × 75 in </Td> <Td> </Td> <Td> 80 cm × 190 cm 31 in × 75 in </Td> <Td> </Td> <Td> 85 cm × 195 cm 33 in × 77 in </Td> <Td> 91 cm × 188 cm 36 in × 74 in </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Th> Single, Twin, or Bunk </Th> <Td> 38 in × 75 in 97 cm × 191 cm </Td> <Td> 92 cm × 188 cm 36 in × 74 in </Td> <Td> 90 cm × 190 cm 35 in × 75 in </Td> <Td> 91 cm × 188 cm 36 in × 74 in </Td> <Td> 90 cm × 200 cm 35 in × 79 in </Td> <Td> 90 cm × 200 cm <P> 35 in × 79 in </P> </Td> <Td> 97 cm × 195 cm 38 in × 77 in </Td> <Td> 106 cm × 188 cm 42 in × 74 in </Td> <Td> 107 cm × 198 cm 42 in × 78 in </Td> <Td> 91 cm × 191 cm 36 in × 75 in </Td> <Td> 88 cm x 188 cm <P> 35 in x 74 in </P> </Td> </Tr> <Tr> <Th> Twin extra long </Th> <Td> 38 in × 80 in 97 cm × 203 cm </Td> <Td> </Td> <Td> </Td> <Td> 91 cm × 203 cm 36 in × 80 in </Td> <Td> 90 cm × 210 cm 35 in × 83 in </Td> <Td> </Td> <Td> 97 cm × 205 cm 38 in × 81 in </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Th> King single or Super single </Th> <Td> </Td> <Td> 107 cm × 203 cm 42 in × 80 in </Td> <Td> </Td> <Td> 107 cm × 203 cm 42 in × 80 in </Td> <Td> 120 cm × 200 cm 47 in × 79 in </Td> <Td> </Td> <Td> 110 cm × 195 cm 43 in × 77 in </Td> <Td> </Td> <Td> </Td> <Td> 107 cm × 191 cm 42 in × 75 in </Td> <Td> 96 cm x 203 cm <P> 38 in x 80 in </P> </Td> </Tr> <Tr> <Th> Small double or Three - quarter </Th> <Td> 48 in × 75 in 122 cm × 191 cm </Td> <Td> </Td> <Td> 120 cm × 190 cm 47 in × 75 in </Td> <Td> </Td> <Td> </Td> <Td> 140 cm × 200 cm <P> 55 in × 79 in </P> </Td> <Td> 122 cm × 195 cm 48 in × 77 in </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Th> Double or Full </Th> <Td> 54 in × 75 in 137 cm × 191 cm </Td> <Td> 138 cm × 188 cm 54 in × 74 in </Td> <Td> 135 cm × 190 cm 53 in × 75 in </Td> <Td> 137 cm × 188 cm 54 in × 74 in </Td> <Td> 140 cm × 200 cm 55 in × 79 in </Td> <Td> 180 cm × 200 cm <P> 71 in × 79 in </P> </Td> <Td> 140 cm × 195 cm 55 in × 77 in </Td> <Td> 152 cm × 188 cm 60 in × 74 in </Td> <Td> 122 cm × 198 cm 48 in × 78 in </Td> <Td> </Td> <Td> 138 cm x 188 cm <P> 54 in x 74 in </P> </Td> </Tr> <Tr> <Th> Double extra long </Th> <Td> 54 in × 80 in 137 cm × 203 cm </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 140 cm × 205 cm 55 in × 81 in </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Th> Queen </Th> <Td> 60 in × 80 in 152 cm × 203 cm </Td> <Td> 153 cm × 203 cm 60 in × 80 in </Td> <Td> </Td> <Td> 153 cm × 203 cm 60 in × 80 in </Td> <Td> </Td> <Td> </Td> <Td> 154 cm × 195 cm 61 in × 77 in </Td> <Td> 182 cm × 188 cm 72 in × 74 in </Td> <Td> 152 cm × 198 cm 60 in × 78 in </Td> <Td> 152 cm × 191 cm 60 in × 75 in </Td> <Td> 158 cm x 198 cm <P> 62 in x 78 in </P> </Td> </Tr> <Tr> <Th> Expanded, Super, or Olympic queen </Th> <Td> 66 in × 80 in 168 cm × 203 cm </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Th> King </Th> <Td> 76 in × 80 in 193 cm × 203 cm or 78 in 198 cm square </Td> <Td> 183 cm × 203 cm 72 in × 80 in </Td> <Td> 152 cm × 198 cm 60 in × 78 in </Td> <Td> 167 cm × 203 cm 66 in × 80 in </Td> <Td> 160 cm × 200 cm 63 in × 79 in </Td> <Td> </Td> <Td> 170 cm × 195 cm 67 in × 77 in </Td> <Td> 182 cm × 212 cm 72 in × 83 in </Td> <Td> 183 cm × 198 cm 72 in × 78 in </Td> <Td> 183 cm × 191 cm 72 in × 75 in </Td> <Td> 193 cm x 203 cm <P> 76 in x 80 in </P> </Td> </Tr> <Tr> <Th> California king or King long </Th> <Td> 72 in × 84 in 183 cm × 213 cm </Td> <Td> 72 in × 84 in 183 cm × 213 cm </Td> <Td> </Td> <Td> 80 in × 80 in 203 cm × 203 cm </Td> <Td> </Td> <Td> </Td> <Td> 170 cm × 205 cm 67 in × 81 in </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Th> Grand king, Super king, Athletic King or Texas king </Th> <Td> 80 in × 98 in 203 cm × 249 cm </Td> <Td> 203 cm × 203 cm 80 in × 80 in </Td> <Td> 180 cm × 200 cm 71 in × 79 in </Td> <Td> 183 cm × 203 cm 72 in × 80 in </Td> <Td> 180 cm × 200 cm <P> 71 in × 79 in </P> </Td> <Td> </Td> <Td> 194 cm × 205 cm 76 in × 81 in </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> </Table> <Tr> <Th> </Th> <Th> US and Canada </Th> <Th> Australia </Th> <Th> Ireland and UK </Th> <Th> New Zealand </Th> <Th> Continental Europe </Th> <Th> Scandinavia </Th> <Th> Japan </Th> <Th> China </Th> <Th> Thailand </Th> <Th> Singapore </Th> <Th> Brazil </Th> </Tr>

Average size of a double bed in cm
find me the text answering this question