Standard book sizes

Books can be any size. Here are the standard sizes to which most books follow:   134 x 197mm (Standard) 216 x 138mm (Demy) 210 x 148mm (A5) 234 x 156mm (Royal) 249 x 177mm (Pinched Crown Quarto) 246 x 189mm (Crown Quarto) 276 x 219mm (Demy Quarto) 297 x 210mm (A4)   it is often cheaper to use one of these.