Companies that sell the merchandise they buy or produce must account for the cost of goods sold, or COGS, to determine gross profits. You can calculate COGS by subtracting the value of ending inventory from the cost of goods available for sale, which is beginning inventory plus inventory purchases. The dollar-value LIFO method allows you to figure ending inventory based on year-to-year changes to the dollar value of inventory after correcting for the effects of inflation.

LIFO Method

The last-in, first-out method assigns inventory costs as if you sell the items you most recently obtained first. Gross profits are your net sales revenues minus COGS. In periods of rising prices, LIFO results in the highest costs and therefore the lowest taxable income. Under LIFO, each time you purchase or produce new inventory, you create a new layer of costs. LIFO liquidation occurs when you exhaust your most recently obtained inventory and must dip into older cost layers, thereby reducing your COGS and increasing your taxable income. The dollar-value LIFO method is a variation of standard LIFO in which you pool inventory costs by year.

Dollar-Value LIFO Pools

In the pooled LIFO method, you assign inventory items to pools based on physical similarity, and you carry the pooled items at average cost for the period. As long as you replenish the pool during the year, you will not create a LIFO liquidation. Under the dollar-value LIFO method, you create pools by year. Instead of grouping items by their physical characteristics, you simply track them by their dollar value, corrected for inflation. You create a new LIFO layer if inventory increases for the year. A decrease is a liquidation. Under the dollar-value LIFO method, you must remove the effects of inflation from each year’s LIFO layer so you can gauge whether increases or decreases to inventory are real or due to inflation.

Cost Indexes

The government releases price indexes that you apply to dollar-value LIFO method layers to remove inflationary effects. If you manufacture your inventory, you use the Producer Price Index; merchandisers use the Consumer Price Index. You can also develop your own index. To remove the effects of inflation, create cost indexes based on annual changes to the appropriate price index. You set the cost index to 100 percent for the year you adopted LIFO, which is the base year. For each subsequent year, you calculate a new cost index based on the year’s percentage change in the price index. You then apply the cost indexes to each year’s ending inventory to figure end-of-year inventory in base-year dollars -- each year of increase creates a new LIFO layer. By reinflating and adding the annual constant-dollar changes to base-year ending inventory cost, you derive the cost of your current ending inventory.


Suppose you adopted LIFO two years ago and have determined your cost indexes to be 100 and 115 percent. Your base-year ending inventory is $200,000, and since the base year is the first year, the change from the previous year is zero. In Year 2, your physical inventory has a cost of $299,000, which you deflate to $260,000 by dividing it by the Year 2 cost index of 115 percent. The real-dollar increase in inventory is $260,000 minus $200,000, or $60,000. To calculate the Year 2 cost layer, multiply the Year 2 layer, $60,000, by the year’s cost index, 115 percent. Add this reinflated result, $69,000, to the base-year ending inventory of $200,000 to get your Year 2 ending dollar-value LIFO inventory of $269,000.