What size is A4, A5, Letter, Half Letter & Personal?

A4 SIZE: 8.3 x 11.7 inches / 210 x 297 mm.

A5 SIZE: 5.8 x 8.3 inches / 148 x 210 mm.

LETTER SIZE: 8.5 x 11 inches / 216 x 279 mm.

HALF LETTER SIZE: 5.5 x 8.5 inches / 140 x 216 mm.

PERSONAL SIZE: 3.75 x 6.75 inches / 95 x 171mm.