In USA, Canada and parts of Mexico you can find the following paper sizes. The 4 most commonly used US standard paper sizes are known as:
The letter paper size is 8.5″ x 11″
(216 mm x 279 mm).
The legal page size is 8.5″ x 14″
(216 mm x 356 mm)
The ledger page size is 11″ x 17″
(279 mm x 432 mm).
The tabloid page size is 17″ x 11″ (432 mm x 279 mm).