Published On:Friday, 16 December 2011
Posted by Muhammad Atif Saeed
Accounting for Inventories
1. Introduction to inventory cost flow methods
Previously when we talked about inventory, we assumed that inventory costs did not change. However, in reality inventory purchase prices fluctuate and that results in varying inventory costs. That is why there is a question of which cost to allocate to the cost of goods sold and the ending inventory at period end.
There are four inventory cost flow methods. The four methods are listed below:
- Specific identification
- First-in, first-out (FIFO)
- Last-in, first-out (LIFO)
- Weighted-average
1.1. Specific identification cost flow method
Companies producing or trading in easily identifiable inventories use the method of specific identification. Cars, airplanes and ships can serve as examples. Each item of inventory is marked, tagged or coded with its "specific" unit cost. This method allows costing of inventory based on its actual physical flow.
Specific identification is an actual physical flow inventory costing method in which items still in inventory are specifically cost to arrive at the total cost of the ending inventory.
This method is difficult to apply by companies that have massive inventory volumes with low unit costs. For instance, it will be hard for a grocery store to keep track of soup cans acquired at different costs. Therefore, grocery stores and similar entities do not apply the method of specific identification.
There is one aspect of the specific identification method that should be mentioned. Management can manipulate the cost of goods sold by selecting which cost will be used in a particular sale transaction. For example, suppose a dealership sells cars. One day the dealership has two identical cars on sale, a Ford costing $5,000 (that was purchased by the company first) and a Ford costing $5,500 (that was acquired by the company after the first Ford). A customer does not care which Ford to get as long as both Fords are identical. However, if the company wants to increase the cost of goods sold (respectively, decrease income), management may sell the $5,500 Ford; if visa versa, then management may sell the $5,000 Ford. So, because the two Fords are identical in physical characteristics and selling price, the customer does not see a difference between the two Fords. However, the dealership may use this to their advantage and manipulate financial statements numbers.
1.2. First-in, first-out (FIFO) cost flow method
The method of first-in, first-out requires that the cost of items purchased first be assigned to the cost of goods sold first.
First-in, first-out (FIFO) inventory costing method assumes that the costs of earliest inventories acquired are the first to be recognized as the cost of goods sold.
In the preceding example, the cost of $5,000 Ford will be assigned to the cost of goods sold.
1.3. Last-in, first-out (LIFO) cost flow method
The method of last-in, first-out assumes that the cost of the goods purchased last is charged to the cost of goods sold first.
Last-in, first-out (LIFO) inventory costing method assumes that the costs of latest inventories acquired are the first to be recognized as the cost of goods sold.
In the example above, the cost of $5,500 Ford will be assigned to the cost of goods sold.
1.4. Weighted-average cost flow method
The weighted-average method (also called the average cost method) provides that the average unit cost is included in the cost of goods sold.
Weighted-average (average cost) inventory costing method assumes that the average cost of inventories is to be recognized as the cost of goods sold.
In order to determine the weighted-average, you need to add all costs of items on hand and divide the result by the number of items. In our example, the calculation is as follows: ($5,000 + $5,500) ÷ 2 = $5,250. This amount will be charged to the cost of goods sold when an item is sold.
It is important to note that the methods described above only refer to cost flows of inventory, and usually not to their physical flows. Physical inventory flows usually follow the specific identification or FIFO rules.
1.5. Effects of different cost flow methods on the income statement
A selected cost flow method has a direct effect on the cost of goods sold and gross margin numbers. Look at the table below and compare the same dealership's gross margins determined using different cost flow methods. Assume that sales are $8,000 and only one car was sold.
Illustration 1: Effect of cost flow methods on gross margin
| | FIFO | LIFO | Weighted - Average |
| Sales | $8,000 | $8,000 | $8,000 |
| Cost of Goods Sold | ($5,000) | ($5,500) | ($5,250) |
| Gross Margin | $3,000 | $2,500 | $2,750 |
Inventory costs are allocated between the cost of goods sold and the ending inventory at period end. Therefore, the cost flow method selected by a company also affects the balance sheet numbers. FIFO transfers the first costs to the income statement leaving the last costs on the balance sheet. Contrary, LIFO moves the last costs to the income statement and retains the first costs on the balance sheet. The weighted-average uses the same average costs for both income statement and balance sheet. Look at the table below to see the balance sheet ending inventory numbers under the three cost flow methods (the same example):
Illustration 2: Effect of cost flow methods on ending inventory balances
| | FIFO | LIFO | Weighted- Average |
| Beginning Inventory | $10,500* | $10,500 | $10,500 |
| Cost of Goods Sold | ($5,000) | ($5,500) | ($5,250) |
| Ending Inventory | $5,500 | $5,000 | $5,250 |
(*) $10,500 = $5,000 + $5,500
2. Application of different cost flow methods
So far we have been talking about two inventory layers with one inventory item (a Ford) in each. In real life companies have multiple inventory layers. In addition, companies can choose between inventory cost flow methods using either perpetual or periodic systems. Combinations of the cost flow methods and systems may result in different numbers in the income statement and on the balance sheet. The following examples will give you a better understanding of inventory cost allocation concepts.
In the discussion below, we will not consider the specific identification method because it is simple and does not require detailed explanations.
Assume that a company named Brid's Drills has the following beginning balance sheet numbers:
Illustration 3: Beginning balances for Brid's Drills
| Assets | | Claims | ||||
| Cash | + | Inventory | = | Contributed Capital | + | Retained Earnings |
| $4,500 | + | $1,500 | = | $4,500 | + | $1,500 |
Consider the following transactions taking place in 20X7:
- Two (2) purchases of drills were made.
- One (1) cash sale of the drills took place.
The table below shows the quantities and costs of inventory layers:
| Beginning Inventory | 100 units x $15 | = | $1,500 | (at cost) |
| Purchase One | 120 units x $18 | = | $2,160 | (at cost) |
| Purchase Two | 80 units x $20 | = | $1,600 | (at cost) |
| | ||||
| Sale | 270 units x $40 | = | $10,800 | (at selling price) |
| Cost of Sale | 270 units x TBD* | = | TBD* | (at cost) |
* TBD - cost to be determined, read further.
In addition, at the end of 20X7 the company paid income taxes based on 30% of net income.
The two inventory purchases have the same effect on the company's financial records under any cost flow method (FIFO, LIFO or weighted-average). The inventory cost balance increases by $3,760 ($2,160 + $1,600) and quantity on hand increases by 200 (120 + 80) units.
The two other transactions (sale and payment of income taxes) differ in amounts under the FIFO, LIFO and weighted-average methods. Let us look at them in more detail.
2.1. Example of FIFO cost flow method
When a sale takes place, two entries are usually made in accounting books. One is for revenue recognition and the other one is for expense (cost of sales or cost of goods sold) recognition. In our example, the revenue recognition entry has the same sales amount regardless of the cost flow method which is $10,800 for 270 drills. The revenue recognition increases both assets (Cash) and equity (by increasing Sales Revenue). This is as asset source transaction.
The cost of goods sold will be different under different cost flow methods. Under FIFO, the cost of goods sold is determined by adding up the costs of 270 drills acquired by Brid's Drills first. The cost of the first 270 units available on hand for Brid's Drills is calculated as follows:
Illustration 4: Brid's Drills cost of goods sold under FIFO
| Beginning Inventory | 100 units x $15 | = | $1,500 |
| Purchase One | 120 units x $18 | = | $2,160 |
| Purchase Two | 50 units x $20 | = | $1,000 |
| Total | 270 units | $4,660 |
The recognition of cost of goods sold decreases assets (Inventory) and equity (by increasing Cost of Goods Sold). The 30 units from the second purchase remain in the Inventory account.
The gross margin and net income equal $6,140 ($10,800 - $4,660). The gross margin and net income are the same in this simplified case because there are no other expenses besides the cost of goods sold. To determine the income tax expense, we need to multiple the net income by the income tax rate. The rate is 30%, so the income tax is $1,842 ($6,140 x 30%). The effect of the income tax payment is a decrease in assets (Cash) and equity (by increasing Income Tax Expenses).
2.2. Example of LIFO cost flow method
Under LIFO, the cost of goods sold is calculated by using the costs of drills purchased last. The computation is shown below:
Illustration 5: Brid's Drills cost of goods sold under LIFO
| Purchase Two | 80 units x $20 | = | $1,600 |
| Purchase One | 120 units x $18 | = | $2,160 |
| Beginning Inventory | 70 units x $15 | = | $1,050 |
| Total | 270 units | $4,810 |
The 30 units from the beginning inventory remain in the Inventory account.
The net income is determined by subtracting the cost of goods sold from sales: $5,990 ($10,800 - $4,810). The income tax to be paid is $1,797 ($5,990 x 30%).
2.3. Example of weighted-average cost flow method
Under this method, the weighted-average cost per unit needs to be calculated first. This is done by dividing the cost of goods available for sale by the number of units available for sale.
Illustration 6: Brid's Drills data for calculating weighted-average cost
| The cost of goods available for sale: |
| 100 x $15 + 120 x $18 + 80 x $20 = $5,260 |
| The number of goods available for sale: |
| 100 + 120 + 80 = 300 units |
Based on the above information, the weighted-average cost per unit is $17.53, rounded to a cent: $5,260 ÷ 300 units.
Next, to determine the cost of goods sold the number of drills sold is multiplied by the weighted-average cost. In our illustration, the cost of goods sold is $4,733.1 ($17.53 x 270 units). The net income is $6,066.9 ($10,800 - $4,733.1) and the income tax is $1,820.07 ($6,066.9 x 30%).
2.4. Summary of cost flow methods
Below you can see the accounting equation, which is partially divided. The first part shows purchase and sale recognition transactions which are the same for any cost flow method. The second presents recognition of the cost of goods sold and income tax payment under different cost flow methods (FIFO, LIFO, and weighted-average).
The transactions are numbered:
1) First purchase of inventory
2) Second purchase of inventory
3a) Sales (revenue) recognition
3b) Expense (cost of goods sold) recognition
4) Income tax payment
Note that some numbers in the table below are rounded.
Illustration 7: Transactions under different cost flow methods for general example
| | Assets | | Claims (Equity) | | | ||||||||||
| # | Cash | + | Inv. | = | Cont. Cap. | + | Ret. Earn. | Rev. | - | Exp. | = | Net Inc. | Cash Flow | ||
| Bal | $4,500 | + | $1,500 | = | $4,500 | + | $1,500 | $ 0 | - | $ 0 | = | $ 0 | | | |
| 1 | (2,160) | + | 2,160 | = | n/a | + | n/a | n/a | - | n/a | = | n/a | (2,160) | OA | |
| 2 | (1,600) | + | 1,600 | = | n/a | + | n/a | n/a | - | n/a | = | n/a | (1,600) | OA | |
| 3a | 10,800 | + | n/a | = | n/a | + | 10,800 | 10,800 | - | n/a | = | 10,800 | 10,800 | OA | |
| FIFO | |||||||||||||||
| 3b | n/a | + | (4,660) | = | n/a | + | (4,660) | n/a | - | 4,660 | = | (4,660) | n/a | | |
| 4 | (1,842) | + | n/a | = | n/a | + | (1,842) | n/a | - | 1,842 | = | (1,842) | (1,842) | OA | |
| Bal | 9,698 | + | 600 | = | 4,500 | + | 5,798 | 10,800 | - | 6,502 | = | 4,298 | 5,198 | | |
| LIFO | |||||||||||||||
| 3b | n/a | + | (4,810) | = | n/a | + | (4,810) | n/a | - | 4,810 | = | (4,810) | n/a | | |
| 4 | (1,797) | + | n/a | = | n/a | + | (1,797) | n/a | - | 1,797 | = | (1,797) | (1,797) | OA | |
| Bal | 9,743 | + | 450 | = | 4,500 | + | 5,693 | 10,800 | - | 6,607 | = | 4,193 | 5,243 | | |
| Weighted-Average | |||||||||||||||
| 3b | n/a | + | (4,733) | = | n/a | + | (4,733) | n/a | - | 4,733 | = | (4,733) | n/a | | |
| 4 | (1,820) | + | n/a | = | n/a | + | (1,820) | n/a | - | 1,820 | = | (1,820) | (1,820) | OA | |
| Bal | 9,720 | + | 527 | = | 4,500 | + | 5,474 | 10,800 | - | 6,553 | = | 4,247 | 5,220 | | |
2.5. Financial statements under different cost flow methods
The net income before taxes, inventory, and cost of goods sold amounts differ under three cost flow methods as shown below:
Illustration 8: Financial statements under different cost flow methods for general example
| Income Statement | |||||
| FIFO | LIFO | Weighted- Average | |||
| Sales | $10,800 | $10,800 | $10,800 | ||
| Cost of Goods Sold | (4,660) | (4,810) | (4,733) | ||
| Gross Margin | 6,140 | 5,990 | 6,067 | ||
| Operating Expenses | 0 | 0 | 0 | ||
| Income before Taxes | 6,140 | 5,990 | 6,067 | ||
| Income Tax Expense | (1,842) | (1,797) | (1,820) | ||
| | | | |||
| Net Income | $4,298 | $4,193 | $4,247 | ||
| | |||||
| Balance Sheet | |||||
| Assets | | | | ||
| Cash | $9,698 | $9,743 | $9,720 | ||
| Inventory | 600 | 450 | 527 | ||
| Total Assets | $10,298 | $10,193 | $10,247 | ||
| | | | |||
| Liabilities | 0 | 0 | 0 | ||
| | | | |||
| Equity | | | | ||
| Contributed Capital | $4,500 | $4,500 | $4,500 | ||
| Retained Earnings | 5,798 | 5,693 | 5,474 | ||
| Total Equity | $10,298 | $10,193 | $10,247 | ||
| | |||||
| Statement of Cash Flows | |||||
| Operating Activities | | | | ||
| Cash Inflow from Sales | $10,800 | $10,800 | $10,800 | ||
| Cash Outflow for Inventory | (3,760)* | (3,760) | (3,760) | ||
| Cash Outflow for Tax | (1,842) | (1,797) | (1,820) | ||
| Net Cash Flow from Operating Activities | $5,198 | $5,243 | $5,220 | ||
| Investing Activities | $ 0 | $ 0 | $ 0 | ||
| Financing Activities | $ 0 | $ 0 | $ 0 | ||
| | | | |||
| Net Increase in Cash | $5,198 | $5,243 | $5,220 | ||
| Beginning Cash Balance | $4,500 | $4,500 | $4,500 | ||
| | | | |||
| Ending Cash Balance | $9,698 | $9,743 | $9,720 | ||
(*) $3,760 = $2,160 + $1,600
You have probably noticed that income before taxes is the highest for FIFO ($6,140) and the lowest for LIFO ($5,990). Why so? Note that the ending inventory balances are just vise versa for FIFO and LIFO (respectively, $600 and $450). Because the cost of goods sold is the difference between the cost of goods available for sale and the ending inventory, the net income before taxes is the highest under the cost flow method that provides for the highest ending inventory balance. Thus, the cost of goods sold under FIFO ($4,660) is lower than the cost of goods sold under LIFO ($4,810).
In conclusion, the net income under the FIFO cost flow method is greater than under the other two methods. Thus, companies that employ FIFO pay higher income taxes. In contrast, companies using LIFO pay lower income taxes.
3. Cost flow methods under different inventory systems (perpetual and periodic)
We have seen how cost flow methods are applied if we have multiple layers, however arranged in a way so that sales go after purchases. But what happens if sales and purchases are mixed, like one purchase is followed by one sale, then again followed up by purchase(s) and sale(s)? In those situations nothing is different and all rules for FIFO, LIFO and weighted-average hold true. The following example will give you a good illustration of applying FIFO and LIFO for sales transactions that occur intermittently with purchases.
Assume a trading company with the following information in the first half of 20X7:
| Jan 1 | Beginning Inventory | 50 units x $10 | (at cost) |
| Feb 25 | Purchase | 100 units x $12 | (at cost) |
| Mar 3 | Sale | 120 units x $20 | (at selling price) |
| Mar 3 | Cost of Sale | 120 units x TBD | (at cost) |
| Apr 6 | Purchase | 60 units x $14 | (at cost) |
| May 17 | Sale | 70 units x $25 | (at selling price) |
| May 17 | Cost of Sale | 70 units x TBD | (at cost) |
TBD - cost to be determined, see below
The total number of goods available for sale for the period is 210 units (50 + 100 + 60).
The total number of goods sold during the period is 190 units (120 + 70).
The ending inventory at period end is 20 units (210 - 190).
The total number of goods sold during the period is 190 units (120 + 70).
The ending inventory at period end is 20 units (210 - 190).
3.1. Example of FIFO cost flow method under perpetual system
Recall that a perpetual inventory system means the inventory accounts are adjusted after each sale or purchase transaction. Under FIFO, the cost of the goods that were acquired by the company first, is transferred from Inventory to Cost of Goods Sold upon a sale. In other words, when a sale takes place, the cost of units from the earliest inventory layer is expensed first. If there are not enough units in the first layer, the unit cost from the next layer is expensed and so on like that.
In our example, on March 3 the company sold 120 units. To calculate the cost of goods sold for the 120 units, we take the 50 units from the first layer (beginning inventory, $10 per unit) and 70 items from the second layer (purchased on February 25, $12 per unit).
Next, on May 17, additional 70 units were sold. The cost of goods sold for the 70 units is computed by adding the cost of 30 (i.e., 100 - 70) units remaining from the second layer (purchased on February 25, $12 per unit) and 40 units from the third layer (purchased on April 6, $14 per unit). The computation of the total cost of goods sold is as follows:
Illustration 9: Example of FIFO cost flow method under perpetual system
| Date | Purchase | Cost of Goods Sold | Inventory | ||||||||||||
| Units | x | Cost | = | Total | Units | x | Cost | = | Total | Units | x | Cost | = | Total | |
| Jan 1 | | | | | | | | | 50 | x | $10 | = | $500 | ||
| Feb 25 | 100 | x | $12 | = | $1,200 | | | | | 50 | x | $10 | = | $500 | |
| | | | | | | | | 100 | x | $12 | = | $1,200 | |||
| Mar 3 | | | | | 50 | x | $10 | = | $500 | | | | | ||
| | | | | 70 | x | $12 | = | $840 | 30 | x | $12 | = | $360 | ||
| Apr 6 | 60 | x | $14 | = | $840 | | | | | 30 | x | $12 | = | $360 | |
| | | | | | | | | 60 | x | $14 | = | $840 | |||
| May 17 | | | | | 30 | x | $12 | = | $360 | | | | | ||
| | | | | 40 | x | $14 | = | $560 | 20 | x | $14 | = | $280 | ||
| | | | | Total COGS | = | $2,260 | End. Inventory | = | $280 | ||||||
3.2. Example of LIFO cost flow method under perpetual system
This method requires that the cost of goods sold be determined by using the cost of units from the latest (newest) inventory layers. Therefore, when figuring out the cost of the 120 units sold on March 3, we need to take into calculation the cost of the 100 items from the second, latest layer (purchased on February 25, $12 per unit) and add the cost of 20 units from the first layer (beginning inventory, $10 per unit). The second layer is used first because it is newer than the first layer (beginning inventory).
As for the sale on May 17, the cost of goods sold is the cost of the 60 items from the third layer (purchased on April 6, $14 per unit) plus the cost of 10 units from the first layer (beginning inventory, $10 per unit). Pay attention that for goods sold on May 17, we could not use the units from the second layer (purchased on February 25) because they had already been used for the sale on March 3. The table below gives you a brief summary of LIFO application:
Illustration 10: Example of LIFO cost flow method under perpetual system
| Date | Purchase | Cost of Goods Sold | Inventory | ||||||||||||
| Units | x | Cost | = | Total | Units | x | Cost | = | Total | Units | x | Cost | = | Total | |
| Jan 1 | | | | | | | | | 50 | x | $10 | = | $500 | ||
| Feb 25 | 100 | x | $12 | = | $120 | | | | | 50 | x | $10 | = | $500 | |
| | | | | | | | | 100 | x | $12 | = | $1,200 | |||
| Mar 3 | | | | | 100 | x | $12 | = | $1,200 | | | | | ||
| | | | | 20 | x | $10 | = | $200 | 30 | x | $10 | = | $300 | ||
| Apr 6 | 60 | x | $14 | = | $840 | | | | | 30 | x | $10 | = | $300 | |
| | | | | | | | | 60 | x | $14 | = | $840 | |||
| May 17 | | | | | 60 | x | $14 | = | $840 | | | | | ||
| | | | | 10 | x | $10 | = | $100 | 20 | x | $10 | = | $200 | ||
| | | | | Total COGS | = | $2,340 | End. Inventory | = | $200 | ||||||
The two preceding examples above show the computations of the cost of goods sold and the ending inventory assuming the perpetual inventory system. Let us move on to the periodic inventory system now.
3.3. Example of FIFO cost flow method under periodic system
Under the periodic system, inventory accounts are not affected when purchases and sales take place. Instead, the Inventory Purchases account is used. The amount of ending inventory is determined by a physical count of inventory on hand at period end. The cost of goods sold is computed by subtracting the amount of ending inventory from the goods available for sale.
Let us assume that the physical count at the end of the first half of 20X7 showed 20 units remaining on hand. The total amount of units sold is therefore 190 (210 - 20).
FIFO means first-in, first-out. So, we need to use the cost of inventories acquired first. Also note that the FIFO method does not require calculation of intermediate amounts of cost of goods sold and ending inventory balances. The cost of goods sold calculation for the 190 units is presented below:
Illustration 11: Example of FIFO cost flow method under periodic system
| From Beginning Inventory on Jan 1 | 50 units x $10 = $500 |
| From Purchase on Feb 25 | 100 units x $12 = $1,200 |
| From Purchase on Apr 6 | 40 units x $14 = $560 |
| Total COGS | $2,260 |
3.4. Example of LIFO cost flow method under periodic system
When calculating the cost of goods sold under LIFO cost flow method, we need to use the cost of inventories acquired last. The computation is shown below:
Illustration 12: Example of LIFO cost flow method under periodic system
| From Purchase on Apr 6 | 60 units x $14 = $840 |
| From Purchase Feb 25 | 100 units x $12 = $1,200 |
| From Beginning Inventory on Jan 1 | 30 units x $10 = $300 |
| Total COGS | $2,340 |
The resulting numbers appeared to be the same for FIFO and LIFO under the inventory perpetual and periodic systems. However, that is not always the case. Sometimes costs of goods sold for LIFO perpetual and LIFO periodic are different.
4. Lower of cost or market rule definition and example
So far we have been looking at methods used to determine inventory costs (more specifically, the cost of goods sold and the ending inventory). Once the cost of ending inventory is calculated, it is required to be compared with the current market value. Comparing the cost to market is the procedure for the lower of cost or market rule.
The market value is the amount that would have been paid to replace the merchandise.
Lower of cost or market rule states that if the market value of ending inventory is lower than the book value of such inventory, the resultant loss must be recognized in the current period.
The lower of cost or market rule can be applied to:
a) Each individual inventory item
b) Major classes or categories of inventory
c) Entire cost of all inventory items
b) Major classes or categories of inventory
c) Entire cost of all inventory items
For example, look at the table below:
Illustration 13: Examples of the lower of cost or market rule
| Item | Cost | Market Value | Lower of Cost or Market |
| A | $500 | $520 | $500 |
| B | $650 | $590 | $590 |
| C | $50 | $50 | $50 |
| D | $12 | $13 | $12 |
| Total | $1,212 | $1,173 | $1,152 |
For individual item A, the cost is lower than the market value, so the lower of cost or market is the cost of $500. For B the market value is lower, so the lower of cost or market is the market value of $590. For item C both the cost and market value are the same, so there is no difference. For item D the cost is lower, so the lower of cost or market is the cost of $12.
As for the aggregate, the total cost of the four items is $1,212, and their total market value is $1,173. So, when applying the lower of cost or market rule to all inventory items in aggregate, the market value of $1,173 needs to be used to adjust the ending inventory balance.
If the market value of an item (or items in aggregate) is lower than its cost, the company has to reduce (write down) the ending inventory balance. For example, in our illustration the difference between the cost in aggregate and the total market value is $39 (i.e., $1,212 - $1,173). If the perpetual inventory system is used, the entry to record this reduction acts to decrease assets (Inventory) and equity (by increasing Cost of Goods Sold or Inventory Loss):
Illustration 14: Effect of inventory costs write-down in the horizontal model
| Assets | = | Liab. | + | Equity | Rev. | - | Exp. | = | Net Inc. | Cash Flows |
| (39) | = | n/a | + | (39) | n/a | - | (39) | = | (39) | n/a |
Illustration 15: Journal entry to write-down inventory costs under perpetual system
| Account Titles | Debit | Credit |
| Dr Cost of Goods Sold (Inventory Loss) | 39 | |
| Cr Inventory | | 39 |
The loss should be shown as an operating expense on the income statement. However, if the amount is immaterial, the loss can be included in the cost of goods sold.
Under periodic inventory system, the amount of ending inventory is automatically shown at the lower of cost or market. The cost of goods sold is computed as the difference between the cost of goods available for sale and the ending inventory. Thus, any decrease in the ending inventory balance due to the application of the lower of cost or market rule increases the cost of goods sold. Assume the following situation:
Illustration 16: Example of the lower of cost or market rule under periodic system
| | Before Applying Rule | After Applying Rrule |
| Beginning Inventory | 1,000 | 1,000 |
| Plus: Purchases | 2,300 | 2,300 |
| Cost of Goods Available for Sale | 3,300 | 3,300 |
| Less: Ending Inventory | (500) | (450) |
| Cost of Goods Sold | 2,800 | 2,850 |
Before application of the lower of cost or market rule, the ending inventory was $500. However, after performing a recalculation of the ending inventory by applying the lower of cost or market rule, the ending inventory was determined to be $450. The difference of $50 is included into the cost of goods sold for the period and no additional adjustment is necessary.
