Introduction
To calculate ending inventory using FIFO, you must understand that this inventory valuation method assumes that the first items purchased (or produced) are the first ones sold. Consider this: by applying FIFO, the cost of the oldest inventory remains in the ending inventory, while the most recent costs flow to cost of goods sold. This approach provides a clear, logical flow of costs and is widely used in retail, manufacturing, and warehousing. In this article we will walk through the concept of FIFO, outline each step required to determine ending inventory, provide a practical example, discuss common pitfalls, and answer frequently asked questions.
Understanding FIFO
What is FIFO?
FIFO stands for first‑in, first‑out, a systematic method where the oldest inventory items are assumed to be sold first. As a result, the remaining items in ending inventory are those that were most recently received or produced.
Why Use FIFO?
- Accurate cost matching – aligns with the physical movement of goods in many businesses.
- Tax advantages – in periods of rising prices, FIFO can result in higher taxable income, which may be desirable for some tax strategies.
- Regulatory compliance – many accounting standards (e.g., IFRS, GAAP) permit FIFO and require consistent application.
Steps to Calculate Ending Inventory Using FIFO
Below is a concise, ordered list of the steps you should follow. Each step includes a brief explanation to ensure clarity.
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Gather all purchase or production data
- Record the date, quantity, and unit cost for every batch of inventory acquired or produced during the period.
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Arrange the data chronologically
- List the batches from the earliest date to the latest date. This chronological order is the backbone of FIFO.
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Determine the total units sold
- From your sales records, calculate the total number of units that were sold during the period.
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Allocate cost to units sold
- Starting with the oldest batch, subtract the sold units from each batch until the total units sold are accounted for.
- Important: Keep a running tally of remaining units in each batch after allocation.
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Identify the batches that constitute ending inventory
- The batches that still have remaining units after step 4 are the ones that make up the ending inventory.
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Calculate the total cost of ending inventory
- Multiply the number of remaining units in each batch by its respective unit cost, then sum these amounts.
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Verify the result
- make sure the sum of units sold plus the units in ending inventory equals the total units available (beginning inventory + purchases/productions).
Example of the Step‑by‑Step Process
Suppose a company has the following inventory activity for the month:
| Date | Units Purchased | Unit Cost | Cumulative Units |
|---|---|---|---|
| Jan 1 | 1,000 | $10 | 1,000 |
| Jan 15 | 500 | $12 | 1,500 |
| Feb 5 | 800 | $11 | 2,300 |
| Mar 10 | 600 | $13 | 2,900 |
Easier said than done, but still worth knowing.
If the company sold 2,200 units during the month, the allocation would be:
- Use all 1,000 units from Jan 1 ($10 each) → 1,000 units sold, $10,000 cost.
- Use 500 units from Jan 15 ($12 each) → 500 units sold, $6,000 cost.
- Use 700 units from Feb 5 ($11 each) → 700 units sold, $7,700 cost.
Total units sold = 2,200; total cost of goods sold = $23,700.
Remaining inventory:
- Feb 5 batch: 100 units left → 100 × $11 = $1,100
- Mar 10 batch: 600 units left → 600 × $13 = $7,800
Ending inventory value = $1,100 + $7,800 = $8,900.
Detailed Calculation Example
Let’s expand the example with a more comprehensive scenario to illustrate the full calculation process.
Scenario
- Beginning inventory (Jan 1): 2,000 units at $9 each.
- Purchase on Jan 20: 1,500 units at $10 each.
- Purchase on Feb 15: 1,000 units at $11 each.
- Sales for the period: 3,200 units.
