## A10 size is the smallest size proposed by A range . It measures only 37 x 26 mm or 1.46 x 1.02 inches. Its surface is therefore 0.00096 m² (or 0.01 square foot, 1.55 square inches).

Its printable area is very limited, it can only be used to print stamps or small coupons. This format can not be used for human writing, except for labels including a single number or a single letter.

A10 meets ISO 216 standard, which was devised in 1975 based on the German DIN 476. This latter was proposed by Walter Portsmann, who took the proposal made by Lichtenberg in 1786 to use the √2 ratio, that is to say a proportion of 1.4142 between sheet’s length and width.

This ratio can keep intact the page’s content when you want to change the format. The width of A(x) becomes indeed automatically length of A(x-1). This last remark does not apply to the A10, since it is the smallest of the A range. If its width is taken to become another smaller size’s length, it will not be recognized by ISO 216 standard .

A10 size is 1024 times smaller than A0, the A size reference. This means that it is necessary to divide the paper weight by 1024 to get the weight of an A10 sheet. For paper of 100 g/m², we get 100/1024 = 0.097 grams.

A10 corresponds to ½ an A9, or ¼ an A8. It takes 32 A10 sheets to form a single A4 sheet.