Methods of inventory valuation include first in first out (FIFO), last in first out (LIFO), and weighted average cost (AVCO). FIFO assumes the earliest goods purchased are sold first and values ending inventory at the latest prices. LIFO assumes the latest goods purchased are sold first and values ending inventory at older prices. AVCO makes no assumptions about inventory movement and values goods based on the weighted average unit cost. The method used affects ending inventory valuation and calculated profits.