An Example Of Fifo Calculation

Use this interactive calculator to work through a practical first in, first out inventory costing example. Enter beginning inventory, purchases, and units sold to calculate cost of goods sold, ending inventory, and the remaining inventory layers under FIFO.

Inventory Inputs

Sales and Display Options

An Example of FIFO Calculation: Complete Expert Guide

FIFO stands for first in, first out. In inventory accounting, that means the oldest goods in stock are assumed to be sold before newer purchases. If a company bought 100 units in January, 150 units in February, and 200 units in March, FIFO assumes the January units leave inventory first when sales happen. This approach matters because the order of costs assigned to sales changes both the reported cost of goods sold and the value of ending inventory.

When people ask for an example of FIFO calculation, they are usually trying to answer one of three practical questions: how much did the sold inventory cost, what value remains in ending inventory, and how do the different purchase layers affect profitability? FIFO is one of the most commonly taught and applied inventory flow assumptions because it is intuitive, straightforward to explain, and often aligns reasonably well with how physical goods move in real operations, especially for perishable or date-sensitive inventory.

What FIFO means in plain language

Imagine a stockroom where the oldest boxes are placed near the front and shipped first. That is essentially the mental model behind FIFO. Under FIFO, the first units purchased are the first units charged to cost of goods sold. Newer purchases stay in ending inventory until earlier layers are exhausted. In periods of rising prices, FIFO usually produces lower cost of goods sold than methods that use newer costs first, because older and cheaper units are assigned to sales. As a result, ending inventory under FIFO often looks higher because it contains the most recent, higher-cost purchases.

FIFO is not just an academic formula. It influences gross profit, taxes, inventory valuation, and management reporting. That is why understanding a clear FIFO example is so important for owners, students, accountants, and analysts.

Core FIFO formula logic

The FIFO process is best understood as a sequence rather than a single formula. You begin with inventory layers. Each layer includes a quantity and a unit cost. Then you subtract units sold starting from the oldest layer. For every layer used, multiply the units taken from that layer by that layer’s unit cost. Add those amounts together to get cost of goods sold. Whatever remains in the newer layers becomes ending inventory.

1. List beginning inventory and each purchase in chronological order.
2. Determine total units available for sale.
3. Enter the number of units sold.
4. Apply the sale to the oldest inventory layer first.
5. Continue until the full sales quantity has been assigned.
6. Sum the assigned costs to compute cost of goods sold.
7. Sum the leftover inventory layers to compute ending inventory.

Step by step FIFO example

Consider a simple business with the following inventory activity for one period:

• Beginning inventory: 100 units at $10 each
• Purchase 1: 150 units at $12 each
• Purchase 2: 200 units at $14 each
• Units sold during the period: 280

Total units available for sale are 450. Under FIFO, the 280 units sold are assigned in this order:

1. Use all 100 beginning inventory units at $10 = $1,000
2. Use all 150 units from Purchase 1 at $12 = $1,800
3. Need 30 more units from Purchase 2 at $14 = $420

That means cost of goods sold is $3,220. The remaining ending inventory is the unused part of Purchase 2, which equals 170 units at $14, or $2,380. This is a classic example of FIFO calculation because you can clearly see how the oldest layers are depleted first and the newest layer remains in ending inventory.

Inventory Layer	Units Available	Unit Cost	Units Assigned to Sales	Cost Assigned	Units Remaining
Beginning Inventory	100	$10.00	100	$1,000.00	0
Purchase 1	150	$12.00	150	$1,800.00	0
Purchase 2	200	$14.00	30	$420.00	170
Total	450		280	$3,220.00	170

Why FIFO often produces higher inventory values in inflationary periods

If purchase costs rise over time, FIFO leaves the most recent and most expensive goods in ending inventory. That tends to increase the ending inventory value reported on the balance sheet. At the same time, cost of goods sold may appear lower than under methods that assign newer costs to sales more quickly. Lower cost of goods sold means higher gross profit, assuming selling prices stay the same.

This is one reason analysts pay close attention to inventory methods when comparing companies. Two firms with identical physical inventory movement could report different accounting results if they apply different cost flow assumptions. FIFO does not change cash collected from customers, but it does affect reported margins and the carrying value of inventory.

Comparison with weighted average cost

To appreciate FIFO better, compare it with weighted average cost using the same data. Total cost of inventory available for sale in our example is:

• 100 × $10 = $1,000
• 150 × $12 = $1,800
• 200 × $14 = $2,800
• Total cost = $5,600

Total units available are 450, so the weighted average cost per unit is $5,600 ÷ 450 = $12.44 approximately. If 280 units were sold, weighted average cost of goods sold would be about $3,483.20, and ending inventory would be about $2,116.80. Compared with FIFO in this rising cost example, weighted average produces a higher cost of goods sold and a lower ending inventory.

Method	Cost of Goods Sold	Ending Inventory	Typical Effect in Rising Prices
FIFO	$3,220.00	$2,380.00	Lower COGS, higher ending inventory
Weighted Average	$3,483.20	$2,116.80	Middle ground smoothing effect

How FIFO appears in real business operations

FIFO is especially common in industries where inventory expiration, freshness, batch dates, or obsolescence matter. Grocery, food service, medical supplies, cosmetics, and seasonal retail are common examples. Even when the accounting method is separate from the warehouse process, the operational logic still makes sense. Companies want older stock used before newer stock to reduce spoilage, markdowns, and storage risk.

Educational and government sources often discuss inventory controls, cost accounting, and stock rotation because these practices influence financial reporting and operational efficiency. For background and broader accounting guidance, review resources from IRS.gov, business education materials from Harvard Business School Online, and accounting learning materials from educational accounting resources. For a more general government source on small business recordkeeping, the U.S. Small Business Administration is also useful.

Important statistics that show why inventory accuracy matters

FIFO calculations are only as good as the underlying quantities and costs. Accurate inventory records are essential. The U.S. Census Bureau regularly reports that manufacturers and merchant wholesalers collectively carry hundreds of billions of dollars in inventories in the United States, demonstrating how material inventory valuation is to the broader economy. Public inventory to sales datasets also show that even small changes in turnover assumptions can affect planning, valuation, and cash management decisions. In practical terms, this means inventory accounting methods are not minor bookkeeping details. They shape how major sectors measure performance.

Reference Point	Observed Statistic	Why It Matters for FIFO
U.S. Census Bureau monthly business inventory series	National business inventories are routinely measured in the hundreds of billions to trillions of dollars across sectors	Inventory valuation methods can have large reporting impacts at scale
Inventory to sales ratio reporting	Even modest ratio changes can influence purchasing and stock planning decisions	FIFO layer tracking helps managers understand what portion of inventory is old versus recent
Small business recordkeeping guidance	Government guidance consistently emphasizes complete purchase and sales records	FIFO depends on reliable chronology and unit cost documentation

Common mistakes in FIFO calculations

• Ignoring chronology: FIFO only works if inventory layers are arranged from oldest to newest.
• Using total cost without layer detail: Total cost alone is not enough unless you are using weighted average.
• Selling more units than available: A valid FIFO result requires enough units in stock.
• Mixing units and dollars: Always compute quantities first, then multiply by the proper layer cost.
• Forgetting beginning inventory: Beginning inventory is usually the oldest layer and must be consumed first.
• Rounding too early: Premature rounding can cause small reporting differences.

How to audit a FIFO answer quickly

You can check a FIFO solution with three fast tests. First, total units sold plus ending units must equal total units available. Second, cost of goods sold plus ending inventory value must equal total cost of goods available for sale. Third, the remaining inventory should be the newest layer or layers, not the oldest ones. If any of these checks fail, the FIFO schedule likely contains an error.

When FIFO is especially useful

FIFO is useful when decision makers want ending inventory to reflect recent costs more closely. Because newer purchases remain in stock under FIFO, the balance sheet often shows a value that is more current than methods that leave older costs in ending inventory. This can help when managers are comparing stock values to current replacement costs. It is also useful pedagogically because it is easy to visualize and explain to stakeholders who do not work in accounting every day.

Practical interpretation of the calculator above

The calculator on this page is designed to show how FIFO works with three layers: beginning inventory and two purchases. That is enough to illustrate the method clearly while staying easy to use. After you click Calculate, the tool identifies how many units from each layer are consumed, computes total cost of goods sold, values the remaining inventory, and charts both sold and unsold units by layer. This makes the FIFO flow visible rather than abstract.

If you want to model your own case, replace the default quantities and costs with your real numbers. If your sales quantity only uses part of the first layer, then ending inventory will include some of the oldest goods. If your sales quantity exceeds the first layer and the second layer, the calculator will continue into the third layer. That is the essence of every FIFO example: deplete the oldest available cost layer first and continue forward until the sale is fully assigned.

Final takeaway

An example of FIFO calculation becomes simple once you think in layers. List inventory in time order, subtract sales from the oldest units first, total the costs assigned to sold units, and then value what remains. In the example used on this page, 280 units sold produced cost of goods sold of $3,220 and ending inventory of $2,380. That outcome reflects the central FIFO rule: older costs go to sales, and newer costs remain in inventory. Whether you are studying accounting, reviewing financial statements, or managing a small business, mastering FIFO gives you a clearer view of both profitability and stock valuation.