The First In First Out method assumes items of stocks are issued in the same order as they are received. Thus the goods received first are assumed to be the first to be issued .Any stock remaining at the end of the accounting period is valued at the actual cost of the equivalent quantities received.FIFO reflects the traditional view of the flow of stock and is a widely used method.

The first in first out (FIFO) method of costing is used to introduce the subject of materials costing. The FIFO method of costing issued materials follows the principle that materials used should carry the actual experienced cost of the specific units used. The method assumes that materials are issued from the oldest supply in stock and that the cost of those units when placed in stock is the cost of those same units when issued. However, FIFO costing may be used even though physical withdrawal is in a different order.